Set Theory

Cardinal Arithmetic

Equation form expr-00ab483201161488

a\cardfont{a}

Read as: the cardinal a

Means: the cardinal a

Equation form expr-01d96bf4bb5c1830

(ω)\cardle{\Pow{\omega}}{\Real}

Read as: the power set of omega has cardinality at most that of the real numbers

Means: the power set of omega has cardinality at most that of the real numbers

Equation form expr-026e768bdc4e4d23

\cardtimes

Read as: cardinal times

Means: cardinal times

Equation form expr-02ec3ef223c1d7a7

|Vα|=α\card{V_\alpha} = \beth_\alpha

Read as: the cardinality of capital V subscript alpha equals beth subscript alpha

Means: the cardinality of capital V subscript alpha equals beth subscript alpha

Equation form expr-055de4ec3d8e4886

κ\kappa

Read as: kappa

Means: kappa

Equation form expr-06809210b9691700

|Vω+α|=α\card{V_{\omega+\alpha}} = \beth_{\alpha}

Read as: the cardinality of capital V subscript omega plus alpha equals beth over alpha

Means: the cardinality of capital V subscript omega plus alpha equals beth over alpha

Equation form expr-0a31e077da6cbc01

aaba\cardfont{a}\leq \cardexpo{\cardfont{a}}{\cardfont{b}} \leq \cardsucc{\cardfont{a}}

Read as: the cardinal a is less than or equal to cardinal exponentiation of the cardinal a to the power the cardinal b

Means: the cardinal a is less than or equal to cardinal exponentiation of the cardinal a to the power the cardinal b

Equation form expr-0aecbac1fa8cd841

|A|1=1|A|=|A|\card{A} \cardplus 1 = 1 \cardplus \card{A} = \card{A}

Read as: the cardinality of capital A cardinal plus one equals one cardinal plus the cardinality of capital A equals the cardinality of capital A

Means: the cardinality of capital A cardinal plus one equals one cardinal plus the cardinality of capital A equals the cardinality of capital A

Equation form expr-0c632ffc56556321

XY\funfromto{X}{Y}

Read as: functions from capital X to capital Y

Means: functions from capital X to capital Y

Equation form expr-0d9ce8fbea95e426

α1,α2\tuple{\alpha_1, \alpha_2}

Read as: the ordered pair alpha subscript one, then alpha subscript two

Means: the ordered pair alpha subscript one, then alpha subscript two

Equation form expr-0da775f751dd03e3

ω=2(ω)\omega = \ordexpo{2}{\omega}

Read as: omega equals ordinal exponentiation of two to the power omega

Means: omega equals ordinal exponentiation of two to the power omega

Equation form expr-0e663e0f57f57a74

nωn \in \omega

Read as: n belongs to omega

Means: n belongs to omega

Equation form expr-113ff1db723874c4

a<2a\cardfont{a} < \cardexpo{2}{\cardfont{a}}

Read as: the cardinal a is less than cardinal exponentiation of two to the power the cardinal a

Means: the cardinal a is less than cardinal exponentiation of two to the power the cardinal a

Equation form expr-11baa595827a4e0f

ω\omega

Read as: omega

Means: omega

Equation form expr-128583a37676f90d

α2=β2\alpha_2 = \beta_2

Read as: alpha subscript two equals beta subscript two

Means: alpha subscript two equals beta subscript two

Equation form expr-16be23d752cb0d6e

XY={f:f is a function XY}\funfromto{X}{Y} = \Setabs{f}{f \text{ is a function } X \to Y}

Read as: functions from capital X to capital Y equals the set of f such that f, is a function, capital X maps to capital Y

Means: functions from capital X to capital Y equals the set of f such that f, is a function, capital X maps to capital Y

Equation form expr-18f5384d58bcb1bb

YY

Read as: capital Y

Means: capital Y

Equation form expr-1b16b1df538ba12d

nn

Read as: n

Means: n

Equation form expr-1b7a9d3ef5f96fc3

ωω×ω\cardeq{\omega}{\omega\times\omega}

Read as: omega is equinumerous with omega times omega

Means: omega is equinumerous with omega times omega

Equation form expr-1c3fc2dbedca59df

VWαV_{W_\alpha}

Read as: capital V subscript capital W subscript alpha

Means: capital V subscript capital W subscript alpha

Equation form expr-1d44b623d7327ce7

αα×α\cardle{\alpha}{\alpha \times \alpha}

Read as: alpha has cardinality at most that of alpha times alpha

Means: alpha has cardinality at most that of alpha times alpha

Equation form expr-1e756bbccd42b487

αω\alpha \geq \omega

Read as: alpha is greater than or equal to omega

Means: alpha is greater than or equal to omega

Equation form expr-208dd57aae84c8ca

ord(α×α,)α\ordtype{\alpha\times \alpha, \canonord} \leq \alpha

Read as: the order type of alpha times alpha precedes in the canonical order is less than or equal to alpha

Means: the order type of alpha times alpha precedes in the canonical order is less than or equal to alpha

Equation form expr-20bb4634e6c63f72

βa\beta \in \cardfont{a}

Read as: beta belongs to the cardinal a

Means: beta belongs to the cardinal a

Equation form expr-22cf6d399835876b

f(γ):baf(\gamma) \colon \cardfont{b} \to \cardfont{a}

Read as: f of gamma colon the cardinal b maps to the cardinal a

Means: f of gamma colon the cardinal b maps to the cardinal a

Equation form expr-26d4eed27a4e196b

b=γb\cardfont{b} = \aleph_{\gamma_\cardfont{b}}

Read as: the cardinal b equals aleph over gamma subscript the cardinal b

Means: the cardinal b equals aleph over gamma subscript the cardinal b

Equation form expr-284c47be48fb0c66

¬\lnot

Read as: negation

Means: negation

Equation form expr-2addffea893434b6

a=(γb)=γb+1\cardfont{a} = \cardsucc{(\aleph_{\gamma_\cardfont{b}})}= \aleph_{\gamma_\cardfont{b}+1}

Read as: the cardinal a equals the cardinal successor of open scope, aleph over gamma subscript the cardinal b, close scope

Means: the cardinal a equals the cardinal successor of open scope, aleph over gamma subscript the cardinal b, close scope

Equation form expr-316bf1f6e4be7245

(ω)\cardle{\Real}{\Pow{\omega}}

Read as: the real numbers has cardinality at most that of the power set of omega

Means: the real numbers has cardinality at most that of the power set of omega

Equation form expr-321563324f37c038

|(A)|=2|A|\card{\Pow{A}} = \cardexpo{2}{\card{A}}

Read as: the cardinality of the power set of capital A equals cardinal exponentiation of two to the power the cardinality of capital A

Means: the cardinality of the power set of capital A equals cardinal exponentiation of two to the power the cardinality of capital A

Equation form expr-33d71f01e44e606a

βb\beta \in \cardfont{b}

Read as: beta belongs to the cardinal b

Means: beta belongs to the cardinal b

Equation form expr-34d6291ebb0c22b3

(A)|A|2\cardeq{\Pow{A}}{\funfromto{\card{A}}{2}}

Read as: the power set of capital A is equinumerous with functions from the cardinality of capital A to two

Means: the power set of capital A is equinumerous with functions from the cardinality of capital A to two

Equation form expr-37071ed0c173c7c5

|(A)|=||A|2|=2|A|\card{\Pow{A}} = \card{\funfromto{\card{A}}{2}} = 2^{\card{A}}

Read as: the cardinality of the power set of capital A equals the cardinality of functions from the cardinality of capital A to two

Means: the cardinality of the power set of capital A equals the cardinality of functions from the cardinality of capital A to two

Equation form expr-394d1165889bcde9

fβ:Xβaf_\beta \colon X_\beta \to \cardfont{a}

Read as: f subscript beta colon capital X subscript beta maps to the cardinal a

Means: f subscript beta colon capital X subscript beta maps to the cardinal a

Equation form expr-3963833522702523

a=b<ab=b<aγb\cardfont{a} = \bigcup_{\cardfont{b} < \cardfont{a}} \cardfont{b} = \bigcup_{\cardfont{b} < \cardfont{a}}{\aleph_{\gamma_\cardfont{b}}}

Read as: the cardinal a equals the union over the cardinal b is less than the cardinal a of the cardinal b

Means: the cardinal a equals the union over the cardinal b is less than the cardinal a of the cardinal b

Equation form expr-398949531980d0f4

α1,α2=β1,β2\tuple{\alpha_1, \alpha_2} = \tuple{\beta_1, \beta_2}

Read as: the ordered pair alpha subscript one, then alpha subscript two equals the ordered pair beta subscript one, then beta subscript two

Means: the ordered pair alpha subscript one, then alpha subscript two equals the ordered pair beta subscript one, then beta subscript two

Equation form expr-40c08a2b7e20d725

κ=κ\kappa = \aleph_\kappa

Read as: kappa equals aleph subscript kappa

Means: kappa equals aleph subscript kappa

Equation form expr-41cc6dcc2adab9ef

|Vκ|=κ=κ\card{V_\kappa} = \beth_\kappa= \kappa

Read as: the cardinality of capital V subscript kappa equals beth subscript kappa

Means: the cardinality of capital V subscript kappa equals beth subscript kappa

Equation form expr-441c7413926a416d

vXβv \in X_\beta

Read as: v belongs to capital X subscript beta

Means: v belongs to capital X subscript beta

Equation form expr-448d6c0708a6613d

vXγv \notin X_\gamma

Read as: v does not belong to capital X subscript gamma

Means: v does not belong to capital X subscript gamma

Equation form expr-4724bf76627efd8a

χB(x)={1if xB0otherwise.\chi_{B}(x) &\defis \begin{cases} 1 & \text{if }x\in B\\ 0 & \text{otherwise.} \end{cases}

Read as: chi subscript capital B of x is defined by cases. case one, one; if, x belongs to capital B. case two, zero; otherwise.. End cases

Means: chi subscript capital B of x is defined by cases. case one, one; if, x belongs to capital B. case two, zero; otherwise.. End cases

Equation form expr-476b9edd51844cb0

0=ω0=ωα+1=(α)α+1=2αα=β<αβα=β<αβwhen α is a limit ordinal.\aleph_{0} &\defis \omega & \beth_{0} &\defis \omega\\ \aleph_{\alpha \ordplus 1} &\defis \cardsucc{(\aleph_{\alpha})} & \beth_{\alpha+1} &\defis \cardexpo{2}{\beth_{\alpha}}\\ \aleph_{\alpha} &\defis \bigcup_{\beta< \alpha} \aleph_{\beta} & \beth_{\alpha} &\defis \bigcup_{\beta < \alpha}\beth_{\beta} & \text{when $\alpha$ is a limit ordinal}.

Read as: Source-ordered display. aleph over zero of is defined as omega applied to beth over zero. Then, aleph over alpha ordinal plus one of is defined as the cardinal successor of open scope, aleph over alpha, close scope beth over alpha plus one. Then, aleph over alpha of is defined as the union over beta is less than alpha of aleph over beta of beth over alpha. End display

Means: Source-ordered display. aleph over zero of is defined as omega applied to beth over zero. Then, aleph over alpha ordinal plus one of is defined as the cardinal successor of open scope, aleph over alpha, close scope beth over alpha plus one. Then, aleph over alpha of is defined as the union over beta is less than alpha of aleph over beta of beth over alpha. End display

Equation form expr-48647d63a534e3e1

|Vκ|=κ\card{V_\kappa} = \kappa

Read as: the cardinality of capital V subscript kappa equals kappa

Means: the cardinality of capital V subscript kappa equals kappa

Equation form expr-4893e9df8b5496eb

α\alpha

Read as: alpha

Means: alpha

Equation form expr-4b68ab3847feda7d

XX

Read as: capital X

Means: capital X

Equation form expr-4bf5f5308abe549f

α×α,\tuple{\alpha \times \alpha, \canonord}

Read as: the ordered pair alpha times alpha, then the canonical order relation

Means: the ordered pair alpha times alpha, then the canonical order relation

Equation form expr-4d2eb930d95d1423

b\cardfont{b}

Read as: the cardinal b

Means: the cardinal b

Equation form expr-4dc190c5ba3f4680

2b<a2b2 \leq \cardfont{b} < \cardfont{a} \leq \cardexpo{2}{\cardfont{b}}

Read as: two is less than or equal to the cardinal b is less than the cardinal a is less than or equal to cardinal exponentiation of two to the power the cardinal b

Means: two is less than or equal to the cardinal b is less than the cardinal a is less than or equal to cardinal exponentiation of two to the power the cardinal b

Equation form expr-4e3c7511020cb010

α×α\alpha \times \alpha

Read as: alpha times alpha

Means: alpha times alpha

Equation form expr-4f1058ece857387f

{max(γ1,γ2):γ1,γ2X}\Setabs{\max(\gamma_1, \gamma_2)}{\tuple{\gamma_1, \gamma_2} \in X}

Read as: the set of the maximum of gamma subscript one, then gamma subscript two such that the ordered pair gamma subscript one, then gamma subscript two belongs to capital X

Means: the set of the maximum of gamma subscript one, then gamma subscript two such that the ordered pair gamma subscript one, then gamma subscript two belongs to capital X

Equation form expr-50232bdef8c40263

|Xβ|a\card{X_\beta} \leq \cardfont{a}

Read as: the cardinality of capital X subscript beta is less than or equal to the cardinal a

Means: the cardinality of capital X subscript beta is less than or equal to the cardinal a

Equation form expr-512a911f16f7706a

|α|α\cardeq{\card{\alpha}}{\alpha}

Read as: the cardinality of alpha is equinumerous with alpha

Means: the cardinality of alpha is equinumerous with alpha

Equation form expr-5157c866e2f2bd7d

1=1\aleph_1 = \beth_1

Read as: aleph subscript one of equals beth subscript one

Means: aleph subscript one of equals beth subscript one

Equation form expr-522df6ad7d1bb5ca

Z\Zminus

Read as: set theory Z minus

Means: set theory Z minus

Equation form expr-528b86f8c38f9730

ab\cardexpo{\cardfont{a}}{\cardfont{b}}

Read as: cardinal exponentiation of the cardinal a to the power the cardinal b

Means: cardinal exponentiation of the cardinal a to the power the cardinal b

Equation form expr-5408911f9f73eddf

ω·ω<κ\omega \ordtimes \omega < \kappa

Read as: omega ordinal times omega is less than kappa

Means: omega ordinal times omega is less than kappa

Equation form expr-54ce300aa2b3e6d6

rank(XY)\setrank{\funfromto{X}{Y}}

Read as: the rank of functions from capital X to capital Y

Means: the rank of functions from capital X to capital Y

Equation form expr-559aead08264d579

AA

Read as: capital A

Means: capital A

Equation form expr-559c63bd803bef5b

γ=max(γ1,γ2)\gamma = \max(\gamma_1, \gamma_2)

Read as: gamma equals the maximum of gamma subscript one, then gamma subscript two

Means: gamma equals the maximum of gamma subscript one, then gamma subscript two

Equation form expr-55d1823545b5b4c3

τ\tau

Read as: tau

Means: tau

Equation form expr-565e5f4eb5e72669

|βaXβ|a\card{\bigcup_{\beta \in \cardfont{a}} X_\beta} \leq \cardfont{a}

Read as: the cardinality of the union over beta belongs to the cardinal a of capital X subscript beta is less than or equal to the cardinal a

Means: the cardinality of the union over beta belongs to the cardinal a of capital X subscript beta is less than or equal to the cardinal a

Equation form expr-576dd5406577b02d

f:(bc)af \colon (\cardfont{b}\disjointsum\cardfont{c}) \to \cardfont{a}

Read as: f colon open scope, the cardinal b disjoint sum the cardinal c, close scope maps to the cardinal a

Means: f colon open scope, the cardinal b disjoint sum the cardinal c, close scope maps to the cardinal a

Equation form expr-5828eda51f773ec9

f:c(ba)f \colon \cardfont{c} \to (\funfromto{\cardfont{b}}{\cardfont{a}})

Read as: f colon the cardinal c maps to open scope, functions from the cardinal b to the cardinal a, close scope

Means: f colon the cardinal c maps to open scope, functions from the cardinal b to the cardinal a, close scope

Equation form expr-583e90eb7865276c

BAB \subseteq A

Read as: capital B is a subset of capital A

Means: capital B is a subset of capital A

Equation form expr-598ca71698daef6a

ω+α=α\omega + \alpha = \alpha

Read as: omega plus alpha equals alpha

Means: omega plus alpha equals alpha

Equation form expr-5c17ab74e47c9426

|α|α\card{\alpha} \in \alpha

Read as: the cardinality of alpha belongs to alpha

Means: the cardinality of alpha belongs to alpha

Equation form expr-5d63b44cd144534c

max(α1,α2)<max(β1,β2)\max(\alpha_1, \alpha_2) < \max(\beta_1, \beta_2)

Read as: the maximum of open scope, alpha subscript one, then alpha subscript two, close scope is less than the maximum of beta subscript one, then beta subscript two

Means: the maximum of open scope, alpha subscript one, then alpha subscript two, close scope is less than the maximum of beta subscript one, then beta subscript two

Equation form expr-5e4eb86e776d9e86

αβ\cardeq{\alpha}{\beta}

Read as: alpha is equinumerous with beta

Means: alpha is equinumerous with beta

Equation form expr-5ed93b3aeb41aeb8

α×αα\cardle{\alpha \times \alpha}{\alpha}

Read as: alpha times alpha has cardinality at most that of alpha

Means: alpha times alpha has cardinality at most that of alpha

Equation form expr-612a23d3904379cf

α\aleph_\alpha

Read as: aleph subscript alpha

Means: aleph subscript alpha

Equation form expr-618d687533fbb236

2bab, as 2a(2a)b, by the lemma on Size Powersettwo Exp=2ab, by proposition five in chapter Cardinal Arithmetic=2b, by theorem two in chapter Cardinal Arithmetic\cardexpo{2}{\cardfont{b}} &\leq \cardexpo{\cardfont{a}}{\cardfont{b}}\text{, as $2 \leq \cardfont{a}$}\\ &\leq \cardexpo{(2^\cardfont{a})}{\cardfont{b}} \text{, by \olref[opps]{lem:SizePowerset2Exp}}\\ &= \cardexpo{2}{\cardfont{a} \cardtimes \cardfont{b}} \text{, by \olref{simplecardexpo}} \\ &= \cardexpo{2}{\cardfont{b}} \text{, by \olref[simp]{cardplustimesmax}}

Read as: Source-ordered display. cardinal exponentiation of two to the power the cardinal b is less than or equal to cardinal exponentiation of the cardinal a to the power the cardinal b , as two is less than or equal to the cardinal a. Then, is less than or equal to cardinal exponentiation of open scope, two superscript the cardinal a, close scope to the power the cardinal b , by the lemma on Size Powersettwo Exp. Then, equals cardinal exponentiation of two to the power the cardinal a cardinal times the cardinal b , by proposition five in chapter Cardinal Arithmetic. Then, equals cardinal exponentiation of two to the power the cardinal b , by theorem two in chapter Cardinal Arithmetic. End display

Means: Source-ordered display. cardinal exponentiation of two to the power the cardinal b is less than or equal to cardinal exponentiation of the cardinal a to the power the cardinal b , as two is less than or equal to the cardinal a. Then, is less than or equal to cardinal exponentiation of open scope, two superscript the cardinal a, close scope to the power the cardinal b , by the lemma on Size Powersettwo Exp. Then, equals cardinal exponentiation of two to the power the cardinal a cardinal times the cardinal b , by proposition five in chapter Cardinal Arithmetic. Then, equals cardinal exponentiation of two to the power the cardinal b , by theorem two in chapter Cardinal Arithmetic. End display

Equation form expr-62c66a7a5dd70c31

mm

Read as: m

Means: m

Equation form expr-64f775ac6ae0544e

α+1\aleph_{\alpha+1}

Read as: aleph over alpha plus one

Means: aleph over alpha plus one

Equation form expr-66d13378c8816533

(ab)(ba)\cardeq{(\cardfont{a} \disjointsum \cardfont{b})}{(\cardfont{b} \disjointsum \cardfont{a})}

Read as: open scope, the cardinal a disjoint sum the cardinal b, close scope is equinumerous with open scope, the cardinal b disjoint sum the cardinal a, close scope

Means: open scope, the cardinal a disjoint sum the cardinal b, close scope is equinumerous with open scope, the cardinal b disjoint sum the cardinal a, close scope

Equation form expr-67610b0632683369

γ\gamma

Read as: gamma

Means: gamma

Equation form expr-67c0a43903195983

β1,β2\tuple{\beta_1, \beta_2}

Read as: the ordered pair beta subscript one, then beta subscript two

Means: the ordered pair beta subscript one, then beta subscript two

Equation form expr-6c31368de4379e34

τ0(A)=|A|τn+1(A)=τn(A)τ(A)=n<ωτn(A)As in proposition twelve in chapter Cardinal Arithmetic, τ(A) is a -fixed point for any A, and trivially |A|<τ(A). So now consider this recursive definition:W0=0Wα+1=τ(Wα)Wα=β<αWβ, when α is a limit\tau_0(A) & \defis \card{A}\\ \tau_{n+1}(A) & \defis \beth_{\tau_n(A)}\\ \tau(A) & \defis \bigcup_{n < \omega}\tau_n(A) \intertext{As in \olref{bethfixed}, $\tau(A)$ is a $\beth$-fixed point for any $A$, and trivially $\card{A} < \tau(A)$. So now consider this recursive definition:} W_0 &\defis 0\\ W_{\alpha + 1} & \defis \tau(W_\alpha)\\ W_\alpha & \defis \bigcup_{\beta < \alpha} W_\beta \text{, when $\alpha$ is a limit}

Read as: Source-ordered display. tau subscript zero of capital A is defined as the cardinality of capital A. Then, tau subscript n plus one of capital A is defined as beth over tau subscript n of capital A. Then, tau of capital A is defined as the union over n is less than omega of tau subscript n of capital A. Then, As in proposition twelve in chapter Cardinal Arithmetic, tau of capital A is a beth-fixed point for any capital A, and trivially the cardinality of capital A is less than tau of capital A. So now consider this recursive definition:. Then, capital W subscript zero is defined as zero. Then, capital W subscript alpha plus one is defined as tau of capital W subscript alpha. Then, capital W subscript alpha is defined as the union over beta is less than alpha of capital W subscript beta, , when alpha is a limit. End display

Means: Source-ordered display. tau subscript zero of capital A is defined as the cardinality of capital A. Then, tau subscript n plus one of capital A is defined as beth over tau subscript n of capital A. Then, tau of capital A is defined as the union over n is less than omega of tau subscript n of capital A. Then, As in proposition twelve in chapter Cardinal Arithmetic, tau of capital A is a beth-fixed point for any capital A, and trivially the cardinality of capital A is less than tau of capital A. So now consider this recursive definition:. Then, capital W subscript zero is defined as zero. Then, capital W subscript alpha plus one is defined as tau of capital W subscript alpha. Then, capital W subscript alpha is defined as the union over beta is less than alpha of capital W subscript beta, , when alpha is a limit. End display

Equation form expr-6e82ac27792a9ac6

\Real

Read as: the real numbers

Means: the real numbers

Equation form expr-6eb2cb875aed951f

an=a\cardexpo{\cardfont{a}}{n} = \cardfont{a}

Read as: cardinal exponentiation of the cardinal a to the power n equals the cardinal a

Means: cardinal exponentiation of the cardinal a to the power n equals the cardinal a

Equation form expr-703c57c85df5fba6

α\beth_\alpha

Read as: beth subscript alpha

Means: beth subscript alpha

Equation form expr-7046857daf500937

ZF\ZF

Read as: set theory Z F

Means: set theory Z F

Equation form expr-705e78cac6bb8e8b

(ω)\cardeq{\Real}{\Pow{\omega}}

Read as: the real numbers is equinumerous with the power set of omega

Means: the real numbers is equinumerous with the power set of omega

Equation form expr-723699f6b0319bc1

α=(ω·ω)+β\alpha = (\omega\ordtimes\omega) \ordplus \beta

Read as: alpha equals open scope, omega ordinal times omega, close scope ordinal plus beta

Means: alpha equals open scope, omega ordinal times omega, close scope ordinal plus beta

Equation form expr-7532402fed19c870

ZFC+¬CH\ZFC + \lnot\text{CH}

Read as: set theory Z F C plus not CH

Means: set theory Z F C plus not CH

Equation form expr-76208888c14b5db6

Bω\Bin^{\omega}

Read as: the set of binary sequences superscript omega

Means: the set of binary sequences superscript omega

Equation form expr-7701c56f6c7ea9fe

α2<β2\alpha_2 < \beta_2

Read as: alpha subscript two is less than beta subscript two

Means: alpha subscript two is less than beta subscript two

Equation form expr-7864d74e178141e7

ω2\funfromto{\omega}{2}

Read as: functions from omega to two

Means: functions from omega to two

Equation form expr-786c3d188fec6489

a=b\cardfont{a} = \cardsucc{\cardfont{b}}

Read as: the cardinal a equals the cardinal successor of the cardinal b

Means: the cardinal a equals the cardinal successor of the cardinal b

Equation form expr-7a045c1ef97d790c

A×BA \times B

Read as: capital A times capital B

Means: capital A times capital B

Equation form expr-7c582c2b017c6fbf

κ<κ\kappa< \aleph_\kappa

Read as: kappa is less than aleph subscript kappa

Means: kappa is less than aleph subscript kappa

Equation form expr-7dd13371e57203fa

aa=aabaaaa\cardfont{a}\cardtimes\cardfont{a} = \cardfont{a} \leq \cardfont{a} \cardplus \cardfont{b} \leq \cardfont{a} \cardplus \cardfont{a} \leq \cardfont{a} \cardtimes \cardfont{a}

Read as: the cardinal a cardinal times the cardinal a equals the cardinal a is less than or equal to the cardinal a cardinal plus the cardinal b is less than or equal to the cardinal a cardinal plus the cardinal a is less than or equal to the cardinal a cardinal times the cardinal a

Means: the cardinal a cardinal times the cardinal a equals the cardinal a is less than or equal to the cardinal a cardinal plus the cardinal b is less than or equal to the cardinal a cardinal plus the cardinal a is less than or equal to the cardinal a cardinal times the cardinal a

Equation form expr-80dd722deb2674b6

b<2b\cardfont{b} < \cardexpo{2}{\cardfont{b}}

Read as: the cardinal b is less than cardinal exponentiation of two to the power the cardinal b

Means: the cardinal b is less than cardinal exponentiation of two to the power the cardinal b

Equation form expr-81a1c5037f99dacd

κ=n<ωκn+1=n<ωκn=α<κα=κ\kappa= \bigcup_{n < \omega} \kappa_{n+1} = \bigcup_{n < \omega}\aleph_{\kappa_n} = \bigcup_{\alpha < \kappa}\aleph_\alpha = \aleph_\kappa

Read as: kappa equals the union over n is less than omega of kappa subscript n plus one equals the union over n is less than omega of aleph over kappa subscript n equals the union over alpha is less than kappa of aleph subscript alpha equals aleph subscript kappa

Means: kappa equals the union over n is less than omega of kappa subscript n plus one equals the union over n is less than omega of aleph over kappa subscript n equals the union over alpha is less than kappa of aleph subscript alpha equals aleph subscript kappa

Equation form expr-81cbb13c1f4a5561

α+1\beth_{\alpha+1}

Read as: beth over alpha plus one

Means: beth over alpha plus one

Equation form expr-84c1bc4c3222ea4b

g:(ω)g \colon \Real \to \Pow{\omega}

Read as: g colon the real numbers maps to the power set of omega

Means: g colon the real numbers maps to the power set of omega

Equation form expr-84e8c34537916246

g:βaXβa×ag \colon \bigcup_{\beta \in \cardfont{a}} X_\beta \to \cardfont{a} \times \cardfont{a}

Read as: g colon the union over beta belongs to the cardinal a of capital X subscript beta maps to the cardinal a times the cardinal a

Means: g colon the union over beta belongs to the cardinal a of capital X subscript beta maps to the cardinal a times the cardinal a

Equation form expr-868fad332b60fd0a

0=0\aleph_0 = \beth_0

Read as: aleph subscript zero of equals beth subscript zero

Means: aleph subscript zero of equals beth subscript zero

Equation form expr-869382de818e47fe

ω+α=ω+((ω·ω)+β)=(ω+(ω·ω))+β=(ω·ω)+β=α\omega \ordplus \alpha = \omega \ordplus ((\omega \ordtimes \omega) \ordplus \beta) = (\omega \ordplus (\omega \ordtimes \omega)) \ordplus \beta = (\omega \ordtimes \omega) \ordplus \beta = \alpha

Read as: omega ordinal plus alpha equals omega ordinal plus open scope, open scope, omega ordinal times omega, close scope ordinal plus beta, close scope equals open scope, omega ordinal plus open scope, omega ordinal times omega, close scope, close scope ordinal plus beta equals open scope, omega ordinal times omega, close scope ordinal plus beta equals alpha

Means: omega ordinal plus alpha equals omega ordinal plus open scope, open scope, omega ordinal times omega, close scope ordinal plus beta, close scope equals open scope, omega ordinal plus open scope, omega ordinal times omega, close scope, close scope ordinal plus beta equals open scope, omega ordinal times omega, close scope ordinal plus beta equals alpha

Equation form expr-8846f8f26404e16f

b<a\cardfont{b} < \cardfont{a}

Read as: the cardinal b is less than the cardinal a

Means: the cardinal b is less than the cardinal a

Equation form expr-8bc9f3d0df963525

a\leq\cardfont{a}

Read as: is less than or equal to the cardinal a

Means: is less than or equal to the cardinal a

Equation form expr-8dd91f8c4b09023d

Xα×αX \subseteq \alpha\times\alpha

Read as: capital X is a subset of alpha times alpha

Means: capital X is a subset of alpha times alpha

Equation form expr-913cf3b881945151

β,γb×c\tuple{\beta, \gamma} \in \cardfont{b} \times \cardfont{c}

Read as: the ordered pair beta, then gamma belongs to the cardinal b times the cardinal c

Means: the ordered pair beta, then gamma belongs to the cardinal b times the cardinal c

Equation form expr-92a21d47df981641

an=aaa=a\cardexpo{\cardfont{a}}{n} = \cardfont{a} \cardtimes \cardfont{a} \cardtimes \ldots \cardtimes \cardfont{a} = \cardfont{a}

Read as: cardinal exponentiation of the cardinal a to the power n equals the cardinal a cardinal times the cardinal a

Means: cardinal exponentiation of the cardinal a to the power n equals the cardinal a cardinal times the cardinal a

Equation form expr-937cdad7cd471979

(ab)c=abc\cardexpo{(\cardexpo{\cardfont{a}}{\cardfont{b}})}{\cardfont{c}} = \cardexpo{\cardfont{a}}{\cardfont{b} \cardtimes \cardfont{c}}

Read as: cardinal exponentiation of open scope, cardinal exponentiation of the cardinal a to the power the cardinal b, close scope to the power the cardinal c equals cardinal exponentiation of the cardinal a to the power the cardinal b cardinal times the cardinal c

Means: cardinal exponentiation of open scope, cardinal exponentiation of the cardinal a to the power the cardinal b, close scope to the power the cardinal c equals cardinal exponentiation of the cardinal a to the power the cardinal b cardinal times the cardinal c

Equation form expr-95a8355b06b66389

rank(X)\setrank{X}

Read as: the rank of capital X

Means: the rank of capital X

Equation form expr-96b71b8ea23f3684

ω·ω=ω·(1+ω)=(ω·1)+(ω·ω)=ω+(ω·ω)\omega \ordtimes \omega = \omega \ordtimes (1 \ordplus \omega) = (\omega \ordtimes 1) \ordplus (\omega\ordtimes\omega) = \omega \ordplus (\omega \ordtimes \omega)

Read as: omega ordinal times omega equals omega ordinal times open scope, one ordinal plus omega, close scope equals open scope, omega ordinal times one, close scope ordinal plus open scope, omega ordinal times omega, close scope equals omega ordinal plus open scope, omega ordinal times omega, close scope

Means: omega ordinal times omega equals omega ordinal times open scope, one ordinal plus omega, close scope equals open scope, omega ordinal times one, close scope ordinal plus open scope, omega ordinal times omega, close scope equals omega ordinal plus open scope, omega ordinal times omega, close scope

Equation form expr-96d0ac49aceb3fbf

a\cardsucc{\cardfont{a}}

Read as: the cardinal successor of the cardinal a

Means: the cardinal successor of the cardinal a

Equation form expr-97320fa1c6111401

fc(γ)=f(γ,1)f_\cardfont{c}(\gamma) = f(\gamma, 1)

Read as: f subscript the cardinal c of gamma equals f of gamma and one

Means: f subscript the cardinal c of gamma equals f of gamma and one

Equation form expr-9836020725b6fff8

0<00 < \aleph_0

Read as: zero is less than aleph subscript zero

Means: zero is less than aleph subscript zero

Equation form expr-9881768c4b7b6085

α×αβ×β\cardeq{\alpha \times \alpha}{\beta \times \beta}

Read as: alpha times alpha is equinumerous with beta times beta

Means: alpha times alpha is equinumerous with beta times beta

Equation form expr-9a89728b4bb49649

γ1,γ2α×α\tuple{\gamma_1, \gamma_2} \in \alpha \times \alpha

Read as: the ordered pair gamma subscript one, then gamma subscript two belongs to alpha times alpha

Means: the ordered pair gamma subscript one, then gamma subscript two belongs to alpha times alpha

Equation form expr-9b4aa9b2f0e1dbea

2ab2 \leq \cardfont{a} \leq \cardfont{b}

Read as: two is less than or equal to the cardinal a is less than or equal to the cardinal b

Means: two is less than or equal to the cardinal a is less than or equal to the cardinal b

Equation form expr-9b5655188745a242

a=max(a,b)\cardfont{a} = \max(\cardfont{a}, \cardfont{b})

Read as: the cardinal a equals the maximum of the cardinal a the empty expression, then the cardinal b

Means: the cardinal a equals the maximum of the cardinal a the empty expression, then the cardinal b

Equation form expr-9e7f4a1822ad8447

\beth

Read as: beth

Means: beth

Equation form expr-9ef714289deedcf5

γβ\gamma \in \beta

Read as: gamma belongs to beta

Means: gamma belongs to beta

Equation form expr-a07d283fa971c66e

γ1,γ2f(γ1),f(γ2)\tuple{\gamma_1, \gamma_2} \mapsto \tuple{f(\gamma_1), f(\gamma_2)}

Read as: the ordered pair gamma subscript one, then gamma subscript two maps to the ordered pair f of gamma subscript one, then f of gamma subscript two

Means: the ordered pair gamma subscript one, then gamma subscript two maps to the ordered pair f of gamma subscript one, then f of gamma subscript two

Equation form expr-a0e54f88d44846e3

γc\gamma \in \cardfont{c}

Read as: gamma belongs to the cardinal c

Means: gamma belongs to the cardinal c

Equation form expr-a45b71f0620cf4b1

a,b,c\cardfont{a}, \cardfont{b}, \cardfont{c}

Read as: the cardinal a the empty expression, then the cardinal b, then the cardinal c

Means: the cardinal a the empty expression, then the cardinal b, then the cardinal c

Equation form expr-a4ef17a629d8bc6c

Seg(γ1,γ2)((γ+1)·(γ+1))(γ·γ), by lemma five in chapter Ordinal Arithmetic and proposition three in chapter Cardinal Arithmeticγ, by the induction hypothesisα, since α is a cardinal\text{Seg}(\gamma_1, \gamma_2) & \precsim ((\gamma \ordplus 1)\ordtimes (\gamma \ordplus 1))\\ &\approx (\gamma \ordtimes \gamma) \text{, by \olref[ord-arithmetic][using-addition]{ordinfinitycharacter} and \olref{simplecardproduct}}\\ &\approx \gamma \text{, by the induction hypothesis}\\ & \prec \alpha\text{, since $\alpha$ is a cardinal}

Read as: Source-ordered display. Seg, open scope, gamma subscript one, then gamma subscript two, close scope is dominated by open scope, open scope, gamma ordinal plus one, close scope ordinal times open scope, gamma ordinal plus one, close scope, close scope. Then, is approximately equal to open scope, gamma ordinal times gamma, close scope, , by lemma five in chapter Ordinal Arithmetic and proposition three in chapter Cardinal Arithmetic. Then, is approximately equal to gamma, , by the induction hypothesis. Then, is strictly less than alpha, , since alpha is a cardinal. End display

Means: Source-ordered display. Seg, open scope, gamma subscript one, then gamma subscript two, close scope is dominated by open scope, open scope, gamma ordinal plus one, close scope ordinal times open scope, gamma ordinal plus one, close scope, close scope. Then, is approximately equal to open scope, gamma ordinal times gamma, close scope, , by lemma five in chapter Ordinal Arithmetic and proposition three in chapter Cardinal Arithmetic. Then, is approximately equal to gamma, , by the induction hypothesis. Then, is strictly less than alpha, , since alpha is a cardinal. End display

Equation form expr-aac6d12ee6adf210

αα×α\cardeq{\alpha}{\alpha \times \alpha}

Read as: alpha is equinumerous with alpha times alpha

Means: alpha is equinumerous with alpha times alpha

Equation form expr-ab0c73e908963f59

rank(Y)\setrank{Y}

Read as: the rank of capital Y

Means: the rank of capital Y

Equation form expr-aba0ac8fc1b46a59

ZFC+GCH\ZFC + \text{GCH}

Read as: set theory Z F C plus GCH

Means: set theory Z F C plus GCH

Equation form expr-ad60575d91fc39d5

a=γ\cardfont{a} = \aleph_\gamma

Read as: the cardinal a equals aleph subscript gamma

Means: the cardinal a equals aleph subscript gamma

Equation form expr-b22e2621b9cb3013

α=α\aleph_\alpha = \beth_\alpha

Read as: aleph subscript alpha of equals beth subscript alpha

Means: aleph subscript alpha of equals beth subscript alpha

Equation form expr-b35a570dd1397cc2

γ=b<aγb\gamma = \bigcup_{\cardfont{b} < \cardfont{a}}\gamma_\cardfont{b}

Read as: gamma equals the union over the cardinal b is less than the cardinal a of gamma subscript the cardinal b

Means: gamma equals the union over the cardinal b is less than the cardinal a of gamma subscript the cardinal b

Equation form expr-b4ba5eea812378b1

ω<2ω\omega < \cardexpo{2}{\omega}

Read as: omega is less than cardinal exponentiation of two to the power omega

Means: omega is less than cardinal exponentiation of two to the power omega

Equation form expr-b4c6291b64161960

0=0=ω\aleph_0 = \beth_0 = \omega

Read as: aleph subscript zero of equals beth subscript zero

Means: aleph subscript zero of equals beth subscript zero

Equation form expr-b4ee0f45f3b6961e

1<11 < \aleph_1

Read as: one is less than aleph subscript one

Means: one is less than aleph subscript one

Equation form expr-b5baefbbb1300da7

Bω\Bin^\omega

Read as: the set of binary sequences superscript omega

Means: the set of binary sequences superscript omega

Equation form expr-b62fb38fa53c3be5

\disjointsum

Read as: disjoint sum

Means: disjoint sum

Equation form expr-b645d837ca596c1a

\aleph

Read as: aleph

Means: aleph

Equation form expr-b9e5414b3f040e8c

κ0=0κn+1=κnκ=n<ωκn\kappa_0 &= 0\\ \kappa_{n+1} &= \aleph_{\kappa_n}\\ \kappa&= \bigcup_{n < \omega}\kappa_n

Read as: Source-ordered display. kappa subscript zero equals zero. Then, kappa subscript n plus one equals aleph over kappa subscript n. Then, kappa equals the union over n is less than omega of kappa subscript n. End display

Means: Source-ordered display. kappa subscript zero equals zero. Then, kappa subscript n plus one equals aleph over kappa subscript n. Then, kappa equals the union over n is less than omega of kappa subscript n. End display

Equation form expr-ba475e3fea4db18b

VκV_\kappa

Read as: capital V subscript kappa

Means: capital V subscript kappa

Equation form expr-bb19a1dc5b65c869

α1=β1\alpha_1 = \beta_1

Read as: alpha subscript one equals beta subscript one

Means: alpha subscript one equals beta subscript one

Equation form expr-bdf15923f1863bda

ab=2b\cardexpo{\cardfont{a}}{\cardfont{b}} = \cardexpo{2}{\cardfont{b}}

Read as: cardinal exponentiation of the cardinal a to the power the cardinal b equals cardinal exponentiation of two to the power the cardinal b

Means: cardinal exponentiation of the cardinal a to the power the cardinal b equals cardinal exponentiation of two to the power the cardinal b

Equation form expr-c04455bd1e7d7d88

Seg(γ1,γ2)={δ1,δ2α×α:δ1,δ2γ1,γ2}\text{Seg}(\gamma_1, \gamma_2) &= \Setabs{\tuple{\delta_1, \delta_2} \in \alpha \times \alpha}{\tuple{\delta_1, \delta_2} \canonord \tuple{\gamma_1, \gamma_2}}

Read as: Seg, open scope, gamma subscript one, then gamma subscript two, close scope equals the set of the ordered pair delta subscript one, then delta subscript two belongs to alpha times alpha such that the ordered pair delta subscript one, then delta subscript two precedes in the canonical order the ordered pair gamma subscript one, then gamma subscript two

Means: Seg, open scope, gamma subscript one, then gamma subscript two, close scope equals the set of the ordered pair delta subscript one, then delta subscript two belongs to alpha times alpha such that the ordered pair delta subscript one, then delta subscript two precedes in the canonical order the ordered pair gamma subscript one, then gamma subscript two

Equation form expr-c1f84ae5ed05d268

ab=a\cardexpo{\cardfont{a}}{\cardfont{b}} = \cardsucc{\cardfont{a}}

Read as: cardinal exponentiation of the cardinal a to the power the cardinal b equals the cardinal successor of the cardinal a

Means: cardinal exponentiation of the cardinal a to the power the cardinal b equals the cardinal successor of the cardinal a

Equation form expr-c2048e02de4999a2

f:αβf \colon \alpha \to \beta

Read as: f colon alpha maps to beta

Means: f colon alpha maps to beta

Equation form expr-c22a834c5dd99eca

ab=|ab|ab=|a×b|ab=|ba|\cardfont{a} \cardplus \cardfont{b} &\defis \card{\cardfont{a} \disjointsum \cardfont{b}}\\ \cardfont{a} \cardtimes \cardfont{b} &\defis \card{\cardfont{a} \times \cardfont{b}}\\ \cardexpo{\cardfont{a}}{\cardfont{b}} &\defis \card{\funfromto{\cardfont{b}}{\cardfont{a}}}

Read as: Source-ordered display. the cardinal a cardinal plus the cardinal b is defined as the cardinality of the cardinal a disjoint sum the cardinal b. Then, the cardinal a cardinal times the cardinal b is defined as the cardinality of the cardinal a times the cardinal b. Then, cardinal exponentiation of the cardinal a to the power the cardinal b is defined as the cardinality of functions from the cardinal b to the cardinal a. End display

Means: Source-ordered display. the cardinal a cardinal plus the cardinal b is defined as the cardinality of the cardinal a disjoint sum the cardinal b. Then, the cardinal a cardinal times the cardinal b is defined as the cardinality of the cardinal a times the cardinal b. Then, cardinal exponentiation of the cardinal a to the power the cardinal b is defined as the cardinality of functions from the cardinal b to the cardinal a. End display

Equation form expr-c552f81100ba4b60

ff*f \mapsto f^*

Read as: f maps to f superscript star

Means: f maps to f superscript star

Equation form expr-c817daca09969708

ab=ab=max(a,b).\cardfont{a} \cardtimes \cardfont{b} = \cardfont{a} \cardplus \cardfont{b} = \text{max}(\cardfont{a}, \cardfont{b}).

Read as: the cardinal a cardinal times the cardinal b equals the cardinal a cardinal plus the cardinal b equals max, open scope, the cardinal a the empty expression, then the cardinal b, close scope

Means: the cardinal a cardinal times the cardinal b equals the cardinal a cardinal plus the cardinal b equals max, open scope, the cardinal a the empty expression, then the cardinal b, close scope

Equation form expr-c81a6a0df60c1020

{γ1,γ2X:max(γ1,γ2)=δ}\Setabs{\tuple{\gamma_1,\gamma_2} \in X}{\max(\gamma_1, \gamma_2) = \delta}

Read as: the set of the ordered pair gamma subscript one, then gamma subscript two belongs to capital X such that the maximum of open scope, gamma subscript one, then gamma subscript two, close scope equals delta

Means: the set of the ordered pair gamma subscript one, then gamma subscript two belongs to capital X such that the maximum of open scope, gamma subscript one, then gamma subscript two, close scope equals delta

Equation form expr-c8949eab46ebfc77

a=ab\cardfont{a} = \cardexpo{\cardfont{a}}{\cardfont{b}}

Read as: the cardinal a equals cardinal exponentiation of the cardinal a to the power the cardinal b

Means: the cardinal a equals cardinal exponentiation of the cardinal a to the power the cardinal b

Equation form expr-c9626e05648546b9

abc=abac\cardexpo{\cardfont{a}}{\cardfont{b} \cardplus \cardfont{c}} = \cardexpo{\cardfont{a}}{\cardfont{b}} \cardtimes \cardexpo{\cardfont{a}}{\cardfont{c}}

Read as: cardinal exponentiation of the cardinal a to the power the cardinal b cardinal plus the cardinal c equals cardinal exponentiation of the cardinal a to the power the cardinal b cardinal times cardinal exponentiation of the cardinal a to the power the cardinal c

Means: cardinal exponentiation of the cardinal a to the power the cardinal b cardinal plus the cardinal c equals cardinal exponentiation of the cardinal a to the power the cardinal b cardinal times cardinal exponentiation of the cardinal a to the power the cardinal c

Equation form expr-c9895046d036ca65

γ1,γ2γ+1,γ+1\tuple{\gamma_1, \gamma_2} \canonord \tuple{\gamma+1, \gamma + 1}

Read as: the ordered pair gamma subscript one, then gamma subscript two precedes in the canonical order the ordered pair gamma plus one, then gamma plus one

Means: the ordered pair gamma subscript one, then gamma subscript two precedes in the canonical order the ordered pair gamma plus one, then gamma plus one

Equation form expr-caf5d72a278bcfcd

2={0,1}2 = \{0, 1\}

Read as: two equals the set containing zero, then one

Means: two equals the set containing zero, then one

Equation form expr-cafaf2312799238d

κ=κ\kappa= \beth_\kappa

Read as: kappa equals beth subscript kappa

Means: kappa equals beth subscript kappa

Equation form expr-cb95c4cb42bc2c4e

ωα\omega \in \alpha

Read as: omega belongs to alpha

Means: omega belongs to alpha

Equation form expr-ce411d89d0f53d5b

(a×b)(b×a)\cardeq{(\cardfont{a} \times \cardfont{b})}{(\cardfont{b} \times \cardfont{a})}

Read as: open scope, the cardinal a times the cardinal b, close scope is equinumerous with open scope, the cardinal b times the cardinal a, close scope

Means: open scope, the cardinal a times the cardinal b, close scope is equinumerous with open scope, the cardinal b times the cardinal a, close scope

Equation form expr-d203ba01eef4198c

δ\delta

Read as: delta

Means: delta

Equation form expr-d318976757631908

αα×α\cardeq{\alpha}{\alpha\times\alpha}

Read as: alpha is equinumerous with alpha times alpha

Means: alpha is equinumerous with alpha times alpha

Equation form expr-d3d79d86ea776a48

f:(A)A2f \colon \Pow{A} \to \funfromto{A}{2}

Read as: f colon the power set of capital A maps to functions from capital A to two

Means: f colon the power set of capital A maps to functions from capital A to two

Equation form expr-d4735e3a265e16ee

22

Read as: two

Means: two

Equation form expr-d7b2a6054576e967

α1<β1\alpha_1 < \beta_1

Read as: alpha subscript one is less than beta subscript one

Means: alpha subscript one is less than beta subscript one

Equation form expr-d87cc01ef52fd93f

\cardplus

Read as: cardinal plus

Means: cardinal plus

Equation form expr-d8824e9378aad1f3

κ=κ\kappa=\aleph_\kappa

Read as: kappa equals aleph subscript kappa

Means: kappa equals aleph subscript kappa

Equation form expr-de25e05e7f7c0144

||=2ω\card{\Real} = \cardexpo{2}{\omega}

Read as: the cardinality of the real numbers equals cardinal exponentiation of two to the power omega

Means: the cardinality of the real numbers equals cardinal exponentiation of two to the power omega

Equation form expr-df264a722a1ae280

bca(ba×ca)\funfromto{\cardfont{b} \disjointsum \cardfont{c}}{\cardfont{a}} \to (\funfromto{\cardfont{b}}{\cardfont{a}} \times \funfromto{\cardfont{c}}{\cardfont{a}})

Read as: functions from the cardinal b disjoint sum the cardinal c to the cardinal a maps to open scope, functions from the cardinal b to the cardinal a times functions from the cardinal c to the cardinal a, close scope

Means: functions from the cardinal b disjoint sum the cardinal c to the cardinal a maps to open scope, functions from the cardinal b to the cardinal a times functions from the cardinal c to the cardinal a, close scope

Equation form expr-df7e70e5021544f4

BB

Read as: capital B

Means: capital B

Equation form expr-e349851823caf578

ZFC\ZFC

Read as: set theory Z F C

Means: set theory Z F C

Equation form expr-e3ebd12aa88a9541

a,b\cardfont{a}, \cardfont{b}

Read as: the cardinal a the empty expression, then the cardinal b

Means: the cardinal a the empty expression, then the cardinal b

Equation form expr-e459021f2080582e

||=1\card{\Real} = \beth_1

Read as: the cardinality of the real numbers equals beth subscript one

Means: the cardinality of the real numbers equals beth subscript one

Equation form expr-e4d28c0b3e89a680

fb(β)=f(β,0)f_\cardfont{b}(\beta) = f(\beta, 0)

Read as: f subscript the cardinal b of beta equals f of beta and zero

Means: f subscript the cardinal b of beta equals f of beta and zero

Equation form expr-e5a69bbb6bda64f3

XβX_\beta

Read as: capital X subscript beta

Means: capital X subscript beta

Equation form expr-e699a88f5fe9eec8

(ω)\Pow{\omega}

Read as: the power set of omega

Means: the power set of omega

Equation form expr-e722e620f9c5a72b

\canonord

Read as: the canonical order relation

Means: the canonical order relation

Equation form expr-e8e03daa6ead8005

f*(β,γ)=(f(γ))(β)f^*(\beta, \gamma) = (f(\gamma))(\beta)

Read as: f superscript star of beta and gamma equals f of gamma applied to beta

Means: f superscript star of beta and gamma equals f of gamma applied to beta

Equation form expr-e9ed9c39c76e6441

f(B)=χBf(B) = \chi_B

Read as: f of capital B equals chi subscript capital B

Means: f of capital B equals chi subscript capital B

Equation form expr-ea0ba03ad68b6f72

(A)A2\cardeq{\Pow{A}}{\funfromto{A}{2}}

Read as: the power set of capital A is equinumerous with functions from capital A to two

Means: the power set of capital A is equinumerous with functions from capital A to two

Equation form expr-ea13392c3c89c82e

2<22 < \aleph_2

Read as: two is less than aleph subscript two

Means: two is less than aleph subscript two

Equation form expr-ebc33acdb2456947

α1,α2β1,β2\tuple{\alpha_1, \alpha_2} \canonord \tuple{\beta_1, \beta_2}

Read as: the ordered pair alpha subscript one, then alpha subscript two precedes in the canonical order the ordered pair beta subscript one, then beta subscript two

Means: the ordered pair alpha subscript one, then alpha subscript two precedes in the canonical order the ordered pair beta subscript one, then beta subscript two

Equation form expr-f0bb9b0835d4f4f6

χBA2\chi_B \in \funfromto{A}{2}

Read as: chi subscript capital B belongs to functions from capital A to two

Means: chi subscript capital B belongs to functions from capital A to two

Equation form expr-f1672d6cf895c128

max(α1,α2)=max(β1,β2)\max(\alpha_1, \alpha_2) = \max(\beta_1, \beta_2)

Read as: the maximum of open scope, alpha subscript one, then alpha subscript two, close scope equals the maximum of beta subscript one, then beta subscript two

Means: the maximum of open scope, alpha subscript one, then alpha subscript two, close scope equals the maximum of beta subscript one, then beta subscript two

Equation form expr-f3f3804480e8551a

β\beta

Read as: beta

Means: beta

Equation form expr-f55d458785a64e48

g(v)=β,fβ(v)g(v) = \tuple{\beta, f_\beta(v)}

Read as: g of v equals the ordered pair beta, then f subscript beta of v

Means: g of v equals the ordered pair beta, then f subscript beta of v

Equation form expr-f6718113dab3a636

ω·ωα\omega \ordtimes \omega \leq \alpha

Read as: omega ordinal times omega is less than or equal to alpha

Means: omega ordinal times omega is less than or equal to alpha

Equation form expr-f72ebed11a3595ce

βaXβa×aa\bigcup_{\beta \in \cardfont{a}} X_\beta \preceq \cardfont{a} \times \cardfont{a} \approx \cardfont{a}

Read as: the union over beta belongs to the cardinal a of capital X subscript beta is less than or equivalent to the cardinal a times the cardinal a is approximately equal to the cardinal a

Means: the union over beta belongs to the cardinal a of capital X subscript beta is less than or equivalent to the cardinal a times the cardinal a is approximately equal to the cardinal a

Equation form expr-f7acd2561ab2bd63

f(fb×fc)f \mapsto (f_{\cardfont{b}} \times f_\cardfont{c})

Read as: f maps to open scope, f subscript the cardinal b times f subscript the cardinal c, close scope

Means: f maps to open scope, f subscript the cardinal b times f subscript the cardinal c, close scope

Equation form expr-f85fa8064284ca5f

c(ba)bca\funfromto{\cardfont{c}}{(\funfromto{\cardfont{b}}{\cardfont{a}})} \to \funfromto{\cardfont{b} \cardtimes \cardfont{c}}{\cardfont{a}}

Read as: functions from the cardinal c to open scope, functions from the cardinal b to the cardinal a, close scope maps to functions from the cardinal b cardinal times the cardinal c to the cardinal a

Means: functions from the cardinal c to open scope, functions from the cardinal b to the cardinal a, close scope maps to functions from the cardinal b cardinal times the cardinal c to the cardinal a

Equation form expr-f926f4e136aa55c9

f:(ω)f \colon \Pow{\omega} \to \Real

Read as: f colon the power set of omega maps to the real numbers

Means: f colon the power set of omega maps to the real numbers

Equation form expr-f972265d166ed1f4

|α||α|×|α|\cardeq{\card{\alpha}}{\card{\alpha} \times \card{\alpha}}

Read as: the cardinality of alpha is equinumerous with the cardinality of alpha times the cardinality of alpha

Means: the cardinality of alpha is equinumerous with the cardinality of alpha times the cardinality of alpha

Equation form expr-fa764ecb38aaa05b

2bab(2b)b=2bb=2b\cardexpo{2}{\cardfont{b}}\leq \cardexpo{\cardfont{a}}{\cardfont{b}} \leq \cardexpo{(\cardexpo{2}{\cardfont{b}})}{\cardfont{b}} = \cardexpo{2}{\cardfont{b}\cardtimes\cardfont{b}} = \cardexpo{2}{\cardfont{b}}

Read as: cardinal exponentiation of two to the power the cardinal b is less than or equal to cardinal exponentiation of the cardinal a to the power the cardinal b

Means: cardinal exponentiation of two to the power the cardinal b is less than or equal to cardinal exponentiation of the cardinal a to the power the cardinal b

Equation form expr-fcb5f40df9be6bae

WW

Read as: capital W

Means: capital W

Equation form expr-fe3756fb5599cf1a

n·mn \cdot m

Read as: n times m

Means: n times m

Equation form expr-ff4be5f76635a0aa

1\beth_1

Read as: beth subscript one

Means: beth subscript one

Definition one in this chapter

This source definition contains, in source order: the cardinal a; then the cardinal b; then Source-ordered display. the cardinal a cardinal plus the cardinal b is defined as the cardinality of the cardinal a disjoint sum the cardinal b. Then, the cardinal a cardinal times the cardinal b is defined as the cardinality of the cardinal a times the cardinal b. Then, cardinal exponentiation of the cardinal a to the power the cardinal b is defined as the cardinality of functions from the cardinal b to the cardinal a. End display; then functions from capital X to capital Y equals the set of f such that f, is a function, capital X maps to capital Y; then functions from capital X to capital Y; then capital X; then capital Y. The complete surrounding source prose remains in the continuous listener stream.

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Display math one in this chapter

This source display math contains, in source order: Source-ordered display. the cardinal a cardinal plus the cardinal b is defined as the cardinality of the cardinal a disjoint sum the cardinal b. Then, the cardinal a cardinal times the cardinal b is defined as the cardinality of the cardinal a times the cardinal b. Then, cardinal exponentiation of the cardinal a to the power the cardinal b is defined as the cardinality of functions from the cardinal b to the cardinal a. End display. The complete surrounding source prose remains in the continuous listener stream.

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Exercise one in this chapter

This source exercise contains, in source order: set theory Z minus; then functions from capital X to capital Y; then capital X; then capital Y; then set theory Z F; then the rank of functions from capital X to capital Y; then the rank of capital X; then the rank of capital Y. The complete surrounding source prose remains in the continuous listener stream. The exercise is preserved as stated and no solution is supplied.

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Proposition one in this chapter

This source proposition contains, in source order: cardinal plus; then cardinal times. The complete surrounding source prose remains in the continuous listener stream.

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Exercise two in this chapter

This source exercise contains, in source order: cardinal plus; then cardinal times. The complete surrounding source prose remains in the continuous listener stream. The exercise is preserved as stated and no solution is supplied.

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Proposition two in this chapter

This source proposition contains, in source order: capital A; then the cardinality of capital A cardinal plus one equals one cardinal plus the cardinality of capital A equals the cardinality of capital A. The complete surrounding source prose remains in the continuous listener stream.

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Lemma one in this chapter

This source lemma contains, in source order: the cardinality of the power set of capital A equals cardinal exponentiation of two to the power the cardinality of capital A; then capital A. The complete surrounding source prose remains in the continuous listener stream.

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Display math two in this chapter

This source display math contains, in source order: chi subscript capital B of x is defined by cases. case one, one; if, x belongs to capital B. case two, zero; otherwise.. End cases. The complete surrounding source prose remains in the continuous listener stream.

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Corollary one in this chapter

This source corollary contains, in source order: the cardinal a is less than cardinal exponentiation of two to the power the cardinal a; then the cardinal a. The complete surrounding source prose remains in the continuous listener stream.

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Theorem one in this chapter

This source theorem contains, in source order: the cardinality of the real numbers equals cardinal exponentiation of two to the power omega. The complete surrounding source prose remains in the continuous listener stream.

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Exercise three in this chapter

This source exercise contains, in source order: the power set of omega has cardinality at most that of the real numbers; then the real numbers has cardinality at most that of the power set of omega. The complete surrounding source prose remains in the continuous listener stream. The exercise is preserved as stated and no solution is supplied.

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Definition two in this chapter

This source definition contains, in source order: the canonical order relation; then the ordered pair alpha subscript one, then alpha subscript two precedes in the canonical order the ordered pair beta subscript one, then beta subscript two; then the maximum of open scope, alpha subscript one, then alpha subscript two, close scope is less than the maximum of beta subscript one, then beta subscript two; then the maximum of open scope, alpha subscript one, then alpha subscript two, close scope equals the maximum of beta subscript one, then beta subscript two; then alpha subscript one is less than beta subscript one; then the maximum of open scope, alpha subscript one, then alpha subscript two, close scope equals the maximum of beta subscript one, then beta subscript two; then alpha subscript one equals beta subscript one; then alpha subscript two is less than beta subscript two. The complete surrounding source prose remains in the continuous listener stream.

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Lemma two in this chapter

This source lemma contains, in source order: the ordered pair alpha times alpha, then the canonical order relation; then alpha. The complete surrounding source prose remains in the continuous listener stream.

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Proposition three in this chapter

This source proposition contains, in source order: alpha is equinumerous with beta; then alpha times alpha is equinumerous with beta times beta. The complete surrounding source prose remains in the continuous listener stream.

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Lemma three in this chapter

This source lemma contains, in source order: alpha is equinumerous with alpha times alpha; then alpha. The complete surrounding source prose remains in the continuous listener stream.

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Display math three in this chapter

This source display math contains, in source order: Seg, open scope, gamma subscript one, then gamma subscript two, close scope equals the set of the ordered pair delta subscript one, then delta subscript two belongs to alpha times alpha such that the ordered pair delta subscript one, then delta subscript two precedes in the canonical order the ordered pair gamma subscript one, then gamma subscript two. The complete surrounding source prose remains in the continuous listener stream.

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Display math four in this chapter

This source display math contains, in source order: Source-ordered display. Seg, open scope, gamma subscript one, then gamma subscript two, close scope is dominated by open scope, open scope, gamma ordinal plus one, close scope ordinal times open scope, gamma ordinal plus one, close scope, close scope. Then, is approximately equal to open scope, gamma ordinal times gamma, close scope, , by the referenced source passage and the referenced source passage. Then, is approximately equal to gamma, , by the induction hypothesis. Then, is strictly less than alpha, , since alpha is a cardinal. End display. The complete surrounding source prose remains in the continuous listener stream.

Source

Theorem two in this chapter

This source theorem contains, in source order: the cardinal a the empty expression, then the cardinal b; then the cardinal a cardinal times the cardinal b equals the cardinal a cardinal plus the cardinal b equals max, open scope, the cardinal a the empty expression, then the cardinal b, close scope. The complete surrounding source prose remains in the continuous listener stream.

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Proposition four in this chapter

This source proposition contains, in source order: the cardinal a; then beta belongs to the cardinal a; then capital X subscript beta; then the cardinality of capital X subscript beta is less than or equal to the cardinal a; then the cardinality of the union over beta belongs to the cardinal a of capital X subscript beta is less than or equal to the cardinal a. The complete surrounding source prose remains in the continuous listener stream.

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Proposition five in this chapter

This source proposition contains, in source order: cardinal exponentiation of the cardinal a to the power the cardinal b cardinal plus the cardinal c equals cardinal exponentiation of the cardinal a to the power the cardinal b cardinal times cardinal exponentiation of the cardinal a to the power the cardinal c; then cardinal exponentiation of open scope, cardinal exponentiation of the cardinal a to the power the cardinal b, close scope to the power the cardinal c equals cardinal exponentiation of the cardinal a to the power the cardinal b cardinal times the cardinal c; then the cardinal a the empty expression, then the cardinal b, then the cardinal c. The complete surrounding source prose remains in the continuous listener stream.

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Proposition six in this chapter

This source proposition contains, in source order: two is less than or equal to the cardinal a is less than or equal to the cardinal b; then the cardinal b; then cardinal exponentiation of the cardinal a to the power the cardinal b equals cardinal exponentiation of two to the power the cardinal b. The complete surrounding source prose remains in the continuous listener stream.

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Display math five in this chapter

This source display math contains, in source order: Source-ordered display. cardinal exponentiation of two to the power the cardinal b is less than or equal to cardinal exponentiation of the cardinal a to the power the cardinal b , as two is less than or equal to the cardinal a. Then, is less than or equal to cardinal exponentiation of open scope, two superscript the cardinal a, close scope to the power the cardinal b , by the referenced source passage. Then, equals cardinal exponentiation of two to the power the cardinal a cardinal times the cardinal b , by the referenced source passage. Then, equals cardinal exponentiation of two to the power the cardinal b , by the referenced source passage. End display. The complete surrounding source prose remains in the continuous listener stream.

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Proposition seven in this chapter

This source proposition contains, in source order: the cardinal a; then n belongs to omega; then cardinal exponentiation of the cardinal a to the power n equals the cardinal a. The complete surrounding source prose remains in the continuous listener stream.

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Proposition eight in this chapter

This source proposition contains, in source order: two is less than or equal to the cardinal b is less than the cardinal a is less than or equal to cardinal exponentiation of two to the power the cardinal b; then the cardinal b; then cardinal exponentiation of the cardinal a to the power the cardinal b equals cardinal exponentiation of two to the power the cardinal b. The complete surrounding source prose remains in the continuous listener stream.

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Definition three in this chapter

This source definition contains, in source order: the cardinal successor of the cardinal a; then the cardinal a; then Source-ordered display. aleph over zero of is defined as omega applied to beth over zero. Then, aleph over alpha ordinal plus one of is defined as the cardinal successor of open scope, aleph over alpha, close scope beth over alpha plus one. Then, aleph over alpha of is defined as the union over beta is less than alpha of aleph over beta of beth over alpha. End display. The complete surrounding source prose remains in the continuous listener stream.

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Display math six in this chapter

This source display math contains, in source order: Source-ordered display. aleph over zero of is defined as omega applied to beth over zero. Then, aleph over alpha ordinal plus one of is defined as the cardinal successor of open scope, aleph over alpha, close scope beth over alpha plus one. Then, aleph over alpha of is defined as the union over beta is less than alpha of aleph over beta of beth over alpha. End display. The complete surrounding source prose remains in the continuous listener stream.

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Proposition nine in this chapter

This source proposition contains, in source order: aleph subscript alpha; then beth subscript alpha; then alpha. The complete surrounding source prose remains in the continuous listener stream.

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Proposition ten in this chapter

This source proposition contains, in source order: the cardinal a; then the cardinal a equals aleph subscript gamma; then gamma. The complete surrounding source prose remains in the continuous listener stream.

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Definition four in this chapter

This source definition contains, in source order: aleph subscript alpha of equals beth subscript alpha; then alpha. The complete surrounding source prose remains in the continuous listener stream.

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Definition five in this chapter

This source definition contains, in source order: aleph subscript one of equals beth subscript one. The complete surrounding source prose remains in the continuous listener stream.

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Proposition eleven in this chapter

This source proposition contains, in source order: aleph. The complete surrounding source prose remains in the continuous listener stream.

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Display math seven in this chapter

This source display math contains, in source order: Source-ordered display. kappa subscript zero equals zero. Then, kappa subscript n plus one equals aleph over kappa subscript n. Then, kappa equals the union over n is less than omega of kappa subscript n. End display. The complete surrounding source prose remains in the continuous listener stream.

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Proposition twelve in this chapter

This source proposition contains, in source order: beth; then kappa; then kappa equals beth subscript kappa. The complete surrounding source prose remains in the continuous listener stream.

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Proposition thirteen in this chapter

This source proposition contains, in source order: the cardinality of capital V subscript omega plus alpha equals beth over alpha; then omega ordinal times omega is less than or equal to alpha; then the cardinality of capital V subscript alpha equals beth subscript alpha. The complete surrounding source prose remains in the continuous listener stream.

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Corollary two in this chapter

This source corollary contains, in source order: kappa; then the cardinality of capital V subscript kappa equals kappa. The complete surrounding source prose remains in the continuous listener stream.

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Display math eight in this chapter

This source display math contains, in source order: Source-ordered display. tau subscript zero of capital A is defined as the cardinality of capital A. Then, tau subscript n plus one of capital A is defined as beth over tau subscript n of capital A. Then, tau of capital A is defined as the union over n is less than omega of tau subscript n of capital A. Then, As in the referenced source passage, tau of capital A is a beth-fixed point for any capital A, and trivially the cardinality of capital A is less than tau of capital A. So now consider this recursive definition:. Then, capital W subscript zero is defined as zero. Then, capital W subscript alpha plus one is defined as tau of capital W subscript alpha. Then, capital W subscript alpha is defined as the union over beta is less than alpha of capital W subscript beta, , when alpha is a limit. End display. The complete surrounding source prose remains in the continuous listener stream.

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Cross-reference reference-001513

lemma four in chapter “Ordinal Arithmetic”

Source occurrence

Cross-reference reference-001514

definition one in chapter “Ordinal Arithmetic”

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Cross-reference reference-001515

proposition in chapter “Sets”

Source occurrence

Cross-reference reference-001516

the lemma on Cardinals Behave Right

Source occurrence

Cross-reference reference-001517

theorem one in chapter “Cardinals”

Source occurrence

Cross-reference reference-001518

lemma five in chapter “Ordinal Arithmetic”

Source occurrence

Cross-reference reference-001519

the lemma on Cardinals Behave Right

Source occurrence

Cross-reference reference-001520

definition of the natural numbers and omega in chapter “Steps towards Z”

Source occurrence

Cross-reference reference-001521

section “Reduction” in chapter “The Size of Sets”

Source occurrence

Cross-reference reference-001522

section “Reduction” in chapter “The Size of Sets”

Source occurrence

Cross-reference reference-001523

the theorem on cantor

Source occurrence

Cross-reference reference-001524

the lemma on Size Powersettwo Exp

Source occurrence

Cross-reference reference-001525

section “Ordinal Exponentiation” in chapter “Ordinal Arithmetic”

Source occurrence

Cross-reference reference-001526

the lemma on Size Powersettwo Exp

Source occurrence

Cross-reference reference-001527

theorem one in chapter “Cardinal Arithmetic”

Source occurrence

Cross-reference reference-001528

proposition “Enumerability of pairs of natural numbers” in chapter “The Size of Sets”

Source occurrence

Cross-reference reference-001529

proposition three in chapter “Cardinal Arithmetic”

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Cross-reference reference-001530

lemma five in chapter “Ordinal Arithmetic”

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Cross-reference reference-001531

proposition three in chapter “Cardinal Arithmetic”

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Cross-reference reference-001532

lemma three in chapter “Cardinal Arithmetic”

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Cross-reference reference-001533

section “Countable Choice” in chapter “Choice”

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Cross-reference reference-001534

theorem two in chapter “Cardinal Arithmetic”

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Cross-reference reference-001535

theorem two in chapter “Cardinal Arithmetic”

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Cross-reference reference-001536

the lemma on Size Powersettwo Exp

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Cross-reference reference-001537

proposition five in chapter “Cardinal Arithmetic”

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Cross-reference reference-001538

theorem two in chapter “Cardinal Arithmetic”

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Cross-reference reference-001539

the lemma on Size Powersettwo Exp

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Cross-reference reference-001540

theorem two in chapter “Cardinal Arithmetic”

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Cross-reference reference-001541

proposition six in chapter “Cardinal Arithmetic”

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Cross-reference reference-001542

the lemma on Size Powersettwo Exp

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Cross-reference reference-001543

the lemma on No Largest Cardinal

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Cross-reference reference-001544

corollary two in chapter “Cardinals”

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Cross-reference reference-001545

proposition three in chapter “Cardinals”

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Cross-reference reference-001546

Kurt Gödel (1938)

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Cross-reference reference-001547

Paul J. Cohen (1963)

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Cross-reference reference-001548

theorem one in chapter “Cardinal Arithmetic”

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Cross-reference reference-001549

Michael Potter (2004), §15.6

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Cross-reference reference-001550

chapter “Stages and Ranks”

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Cross-reference reference-001551

proposition three in chapter “Cardinals”

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Cross-reference reference-001552

(George Boolos, 2000, p. 257)

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Cross-reference reference-001553

(George Boolos, 2000, p. 268)

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Cross-reference reference-001554

section “Extrinsic Considerations about Replacement” in chapter “Replacement”

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Cross-reference reference-001555

proposition eleven in chapter “Cardinal Arithmetic”

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Cross-reference reference-001556

chapter “Ordinal Arithmetic”

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Cross-reference reference-001557

proposition twelve in chapter “Cardinal Arithmetic”

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Cross-reference reference-001558

proposition thirteen in chapter “Cardinal Arithmetic”

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Cross-reference reference-001559

proposition twelve in chapter “Cardinal Arithmetic”

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