Many-valued logics

Infinite-valued Logics

Equation form expr-01208e159d2aec8c

\land

Read as: conjunction

Means: conjunction

Equation form expr-043b130790fae68b

¬AB\lnot !A \lor !B

Read as: the disjunction of not A with B

Means: the disjunction of not A with B

Equation form expr-05337f415c1099c6

~=0¬~G(x)={1if x=00otherwise~G(x,y)=min(x,y)~G(x,y)=max(x,y)~G(x,y)={1if xyyotherwise.\tf{\lfalse} & = 0\\ \tf{\lnot}[\LogGod](x) & = \begin{cases} $1$ & \text{if } x =0\\ $0$ & \text{otherwise} \end{cases}\\ \tf{\land}[\LogGod](x,y) & = \min(x,y)\\ \tf{\lor}[\LogGod](x,y) & = \max(x,y)\\ \tf{\lif}[\LogGod](x,y) & = \begin{cases} 1 & \text{if } x \le y\\ y & \text{otherwise.} \end{cases}

Read as: Goedel truth functions. Falsity has value zero. Negation of x has value one if x equals zero, and zero otherwise. Conjunction of x and y has the minimum of x and y as its value. Disjunction has their maximum as its value. The conditional with antecedent value x and consequent value y has value one if x is less than or equal to y, and value y otherwise. End of truth function definitions.

Means: Goedel truth functions. Falsity has value zero. Negation of x has value one if x equals zero, and zero otherwise. Conjunction of x and y has the minimum of x and y as its value. Disjunction has their maximum as its value. The conditional with antecedent value x and consequent value y has value one if x is less than or equal to y, and value y otherwise. End of truth function definitions.

Equation form expr-069ac2aed6bc166f

~Ł3\tf{\lif}[\LogLuk[3]]

Read as: the three valued Lukasiewicz conditional truth function

Means: the three valued Lukasiewicz conditional truth function

Equation form expr-0fc07e559bd4cc67

m2m \ge 2

Read as: m greater than or equal to two

Means: m greater than or equal to two

Equation form expr-16f38629e1f81ade

Ł3\LogLuk[3]

Read as: three valued Lukasiewicz logic

Means: three valued Lukasiewicz logic

Equation form expr-1a47830e263c0c3b

(pq)(qr)(rs)(p \lif q) \lor (q \lif r) \lor (r \lif s)

Read as: the disjunction of the three conditionals: if p then q; if q then r; and if r then s

Means: the disjunction of the three conditionals: if p then q; if q then r; and if r then s

Equation form expr-1c09ff1165c1a636

V[0,1]=[0,1]V_{[0,1]} = [0,1]

Read as: V subscript the closed interval from zero to one equals that closed interval

Means: V subscript the closed interval from zero to one equals that closed interval

Equation form expr-1d06c3cd92e108cd

G\LogGod[\infty]

Read as: G subscript infinity

Means: G subscript infinity

Equation form expr-20ddfc618734c4ad

~G\tf{\lor}[\LogGod]

Read as: the Goedel disjunction truth function

Means: the Goedel disjunction truth function

Equation form expr-284c47be48fb0c66

¬\lnot

Read as: negation

Means: negation

Equation form expr-2f31c694e82f1471

V={nm:n,m and nm}.When considering this infinite truth value set, it is often useful to also consider the subsetsVm={nm1:n and nm}For instance, V5 is the set with 5 evenly spaced truth values,V5={0,14,12,34,1}.V_\infty & = \Setabs{\frac{n}{m}}{n,m \in \Nat \text{ and } n\le m}. \intertext{When considering this infinite truth value set, it is often useful to also consider the subsets} V_m & = \Setabs{\frac{n}{m-1}}{n \in \Nat \text{ and } n\le m} \intertext{For instance, $V_5$ is the set with $5$ evenly spaced truth values,} V_5 & = \{0, \frac{1}{4}, \frac{1}{2}, \frac{3}{4}, 1\}.

Read as: V subscript infinity equals the set of fractions n divided by m such that n and m are natural numbers and n is less than or equal to m. When considering this infinite truth value set, it is often useful to also consider the subsets V subscript m, which the source writes as the set of n divided by the quantity m minus one, such that n is a natural number and n is less than or equal to m. For instance, V subscript five is the set with five evenly spaced truth values: V subscript five equals the set containing zero, one quarter, one half, three quarters, and one. End of displayed value sets.

Means: V subscript infinity equals the set of fractions n divided by m such that n and m are natural numbers and n is less than or equal to m. When considering this infinite truth value set, it is often useful to also consider the subsets V subscript m, which the source writes as the set of n divided by the quantity m minus one, such that n is a natural number and n is less than or equal to m. For instance, V subscript five is the set with five evenly spaced truth values: V subscript five equals the set containing zero, one quarter, one half, three quarters, and one. End of displayed value sets.

Equation form expr-3163c74b28295918

~Ł3\tf{\lor}[\LogLuk[3]]

Read as: the three valued Lukasiewicz disjunction truth function

Means: the three valued Lukasiewicz disjunction truth function

Equation form expr-463f2998327eb3a6

[0,1][0,1]

Read as: the closed interval from zero to one

Means: the closed interval from zero to one

Equation form expr-529ad2daacd7efcb

\lor

Read as: disjunction

Means: disjunction

Equation form expr-58197ff8ca27696b

¬~\tf{\lnot}

Read as: the negation truth function

Means: the negation truth function

Equation form expr-59762fad561b366c

LC\Log{LC}

Read as: L C

Means: L C

Equation form expr-5d94be88a66c614f

~G\tf{\lif}[\LogGod]

Read as: the Goedel conditional truth function

Means: the Goedel conditional truth function

Equation form expr-5feceb66ffc86f38

00

Read as: zero

Means: zero

Equation form expr-62c66a7a5dd70c31

mm

Read as: m

Means: m

Equation form expr-6b4edfc5fe38d079

G3\LogGod[3]

Read as: three valued Goedel logic

Means: three valued Goedel logic

Equation form expr-6b86b273ff34fce1

11

Read as: one

Means: one

Equation form expr-79b01b537984bd57

V=[0,1]V_\infty = [0,1] \cap \Rat

Read as: V subscript infinity equals the intersection of the closed interval from zero to one with the rational numbers

Means: V subscript infinity equals the intersection of the closed interval from zero to one with the rational numbers

Equation form expr-8124eb9a8372e942

~G\tf{\land}[\LogGod]

Read as: the Goedel conjunction truth function

Means: the Goedel conjunction truth function

Equation form expr-82623f345da734fd

~Ł3\tf{\land}[\LogLuk[3]]

Read as: the three valued Lukasiewicz conjunction truth function

Means: the three valued Lukasiewicz conjunction truth function

Equation form expr-87b3f0a70b64ebaf

¬~G3\tf{\lnot}[\LogGod[3]]

Read as: the three valued Goedel negation truth function

Means: the three valued Goedel negation truth function

Equation form expr-8fb9f63317f1a904

¬~Ł(x)=1x~Ł(x,y)=min(x,y)~Ł(x,y)=max(x,y)~Ł(x,y)=min(1,1(xy))={1if xy1(xy)otherwise.\tf{\lnot}[\LogLuk](x) & = 1 - x\\ \tf{\land}[\LogLuk](x,y) & = \min(x,y)\\ \tf{\lor}[\LogLuk](x,y) & = \max(x,y)\\ \tf{\lif}[\LogLuk](x,y) & = \min(1,1-(x-y)) = \begin{cases} 1 & \text{if } x \le y\\ 1-(x-y) & \text{otherwise.} \end{cases}

Read as: Lukasiewicz truth functions. Negation of x has value one minus x. Conjunction of x and y has the minimum of x and y as its value. Disjunction has their maximum as its value. The conditional with antecedent value x and consequent value y has value the minimum of one and the quantity one minus the difference x minus y. Equivalently, its value is one if x is less than or equal to y, and one minus the difference x minus y otherwise. End of truth function definitions.

Means: Lukasiewicz truth functions. Negation of x has value one minus x. Conjunction of x and y has the minimum of x and y as its value. Disjunction has their maximum as its value. The conditional with antecedent value x and consequent value y has value the minimum of one and the quantity one minus the difference x minus y. Equivalently, its value is one if x is less than or equal to y, and one minus the difference x minus y otherwise. End of truth function definitions.

Equation form expr-9244c801c50f58fd

(pq)(qp)(p \lif q) \lor (q \lif p)

Read as: the disjunction of if p then q with if q then p

Means: the disjunction of if p then q with if q then p

Equation form expr-9ef1dd9e99e03eb0

ΓŁmB\Gamma \Entails[\LogLuk[m]] !B

Read as: Gamma entails B in m valued Lukasiewicz logic

Means: Gamma entails B in m valued Lukasiewicz logic

Equation form expr-ab2c0c588ded3e79

V=VmV = V_m

Read as: V equals V subscript m

Means: V equals V subscript m

Equation form expr-ad9293b54c2b636f

(AB)(BA)(!A \lif !B) \lor (!B \lif !A)

Read as: the disjunction of if A then B with if B then A

Means: the disjunction of if A then B with if B then A

Equation form expr-b1c615d83e93e6d0

ΓGB\Gamma \Entails[\LogGod[\infty]] !B

Read as: Gamma entails B in infinite valued Goedel logic

Means: Gamma entails B in infinite valued Goedel logic

Equation form expr-b85f62f6e470cee8

ΓŁB\Gamma \Entails[\LogLuk[\infty]] !B

Read as: Gamma entails B in infinite valued Lukasiewicz logic

Means: Gamma entails B in infinite valued Lukasiewicz logic

Equation form expr-bd91dd8f754d52fc

VV_\infty

Read as: V subscript infinity

Means: V subscript infinity

Equation form expr-be94b5694f7121c8

V+={1}V^+ = \{1\}

Read as: the designated value set V plus is the singleton set containing one

Means: the designated value set V plus is the singleton set containing one

Equation form expr-cdc2ed7d3b3d72c2

\lfalse

Read as: the falsity constant

Means: the falsity constant

Equation form expr-d04ff80d9f6dc462

\lif

Read as: conditional

Means: conditional

Equation form expr-d0d17125f775c2da

ΓGmB\Gamma \Entails[\LogGod[m]] !B

Read as: Gamma entails B in m valued Goedel logic

Means: Gamma entails B in m valued Goedel logic

Equation form expr-d4e220a9305a8728

Ł\LogLuk[\infty]

Read as: L subscript infinity

Means: L subscript infinity

Equation form expr-d72c2cedf15e5fa4

L0\Lang L_0

Read as: L subscript zero

Means: L subscript zero

Equation form expr-d939926f05444b0f

1/21/2

Read as: one half

Means: one half

Equation form expr-de5a6f78116eca62

VV

Read as: V

Means: V

Equation form expr-e54931a36854f35f

p¬p(pq)(¬pq)¬¬pp¬(¬p¬q)(pq)((pq)p)p¬(pq)(p¬q)& p \lor \lnot p && (p \lif q) \lif (\lnot p \lor q) \\ & \lnot\lnot p \lif p && \lnot(\lnot p \land \lnot q) \lif (p \lor q) \\ & ((p \lif q) \lif p) \lif p && \lnot(p \lif q) \lif (p \land \lnot q)

Read as: Six formulas, read across each source row from left to right. Row one, left: p or not p. Row one, right: if the conditional if p then q holds, then not p or q. Row two, left: if not not p then p. Row two, right: if it is not the case that both not p and not q, then p or q. Row three, left: if the conditional from if p then q to p holds, then p. Row three, right: if it is not the case that if p then q, then both p and not q. End of six formulas.

Means: Six formulas, read across each source row from left to right. Row one, left: p or not p. Row one, right: if the conditional if p then q holds, then not p or q. Row two, left: if not not p then p. Row two, right: if it is not the case that both not p and not q, then p or q. Row three, left: if the conditional from if p then q to p holds, then p. Row three, right: if it is not the case that if p then q, then both p and not q. End of six formulas.

Infinite and finite sets of truth values

The display gives a rational value set, a finite evenly spaced value set, and the five element example zero, one quarter, one half, three quarters and one. The source finite-set upper bound and omitted denominator restriction are retained with a caveat.

Source

Infinite and finite valued Lukasiewicz matrices

Only one is designated. Negation is one minus the input, conjunction is minimum, disjunction is maximum, and the conditional is the minimum of one and one minus the difference of antecedent and consequent values. The finite version restricts the value set. The source identifies this section as a stub.

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Lukasiewicz truth function equations

The displayed conditional has two branches: one when the antecedent value is at most the consequent value, and one minus their difference otherwise. The subtraction groups the antecedent minus consequent difference as a whole.

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Agreement of the two three valued Lukasiewicz definitions

The proposition identifies the earlier symbolic true, undefined and false truth tables with the numeric values one, one half and zero, respectively. Four tables demonstrate the agreement.

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Numeric Lukasiewicz negation table

In source input order one, one half, zero, negation gives zero, one half, one respectively.

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Numeric Lukasiewicz conjunction table

Both input axes are ordered one, one half, zero. Each result is the lesser input. The full source row sequence is retained in the separate table reading.

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Numeric Lukasiewicz disjunction table

Both input axes are ordered one, one half, zero. Each result is the greater input. The full source row sequence is retained in the separate table reading.

Source

Numeric Lukasiewicz conditional table

Rows are antecedent values and columns consequent values, each ordered one, one half, zero. The middle row is one, one, one half, distinguishing this conditional from the Goedel conditional.

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From infinite to finite Lukasiewicz consequence

Consequence in infinite valued Lukasiewicz logic implies consequence in each m valued version for every m at least two. The proof is left as an exercise; the subsequent source sentence also states the converse without proving it.

Source

Exercise on restricting Lukasiewicz truth values

Prove that infinite valued consequence implies consequence for every finite number of values at least two. No solution is supplied.

Source

Exercise on Lukasiewicz prelinearity

Show that the disjunction of if p then q and if q then p is a tautology of infinite valued Lukasiewicz logic. No solution is supplied.

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Infinite and finite valued Goedel matrices

Only one is designated. Falsity is zero; negation is one only at zero and otherwise zero; conjunction is minimum; disjunction is maximum. The conditional is one when antecedent is at most consequent and otherwise equals the consequent. The source identifies this section as a stub.

Source

Goedel truth function equations

The equations include a zero-valued falsity constant and explicit two-branch definitions of negation and conditional. Negation at a positive intermediate value is zero, not its complement.

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Agreement of the two three valued Goedel definitions

The proposition identifies the earlier symbolic truth values with one, one half and zero. The following four numeric tables show the same truth functions.

Source

Numeric Goedel negation table

In source input order one, one half, zero, negation gives zero, zero, one respectively.

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Numeric Goedel conjunction table

Both axes are ordered one, one half, zero, and each cell is their minimum. All rows and cells are explicitly linearized.

Source

Numeric Goedel disjunction table

Both axes are ordered one, one half, zero, and each cell is their maximum. All rows and cells are explicitly linearized.

Source

Numeric Goedel conditional table

Rows are antecedent values and columns consequent values, each ordered one, one half, zero. The middle row is one, one, zero. That final zero differs from the one half in Lukasiewicz logic.

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From infinite to finite Goedel consequence

Consequence in infinite valued Goedel logic implies consequence in each m valued version for every m at least two. The source leaves the proof to an exercise and subsequently states the converse without proof.

Source

Exercise on restricting Goedel truth values

Prove the preceding implication from infinite valued Goedel consequence to every finite valued version with at least two values. No solution is supplied.

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Six non-tautologies of Goedel logic

The source arranges six formulas in three rows and two columns. They are read across each row, left then right, retaining scope. The list includes excluded middle, double negation elimination and Peirce law among other formulas.

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Exercise on Goedel prelinearity

Show that the disjunction of if p then q with if q then p is a tautology of infinite valued Goedel logic. No solution is supplied.

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Exercise separating finite and infinite Goedel tautologies

Show that the disjunction of the three conditionals from p to q, q to r, and r to s, which is a three valued Goedel tautology, is not an infinite valued Goedel tautology. No solution is supplied.

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Cross-reference reference-000928

the earlier three valued Lukasiewicz matrix definition

Source occurrence

Cross-reference reference-000929

the infinite and finite valued Lukasiewicz matrix definition

Source occurrence

Cross-reference reference-000930

the earlier three valued Lukasiewicz matrix definition

Source occurrence

Cross-reference reference-000931

the infinite and finite valued Lukasiewicz matrix definition

Source occurrence

Cross-reference reference-000932

the proposition on restricting infinite Lukasiewicz consequence to finitely many values

Source occurrence

Cross-reference reference-000933

the earlier three valued Goedel matrix definition

Source occurrence

Cross-reference reference-000934

the infinite and finite valued Goedel matrix definition

Source occurrence

Cross-reference reference-000935

the earlier three valued Goedel matrix definition

Source occurrence

Cross-reference reference-000936

the infinite and finite valued Goedel matrix definition

Source occurrence

Cross-reference reference-000937

the proposition on restricting infinite Goedel consequence to finitely many values

Source occurrence

Source disclosures