Definition:Truth Function/Connective

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Definition

The logical connectives are assumed to be truth-functional.

Hence, they are represented by certain truth functions.


Logical Negation

The logical not connective defines the truth function $f^\neg$ as follows:

\(\ds \map {f^\neg} \F\) \(=\) \(\ds \T\)
\(\ds \map {f^\neg} \T\) \(=\) \(\ds \F\)


Logical Conjunction

The conjunction connective defines the truth function $f^\land$ as follows:

\(\ds \map {f^\land} {\F, \F}\) \(=\) \(\ds \F\)
\(\ds \map {f^\land} {\F, \T}\) \(=\) \(\ds \F\)
\(\ds \map {f^\land} {\T, \F}\) \(=\) \(\ds \F\)
\(\ds \map {f^\land} {\T, \T}\) \(=\) \(\ds \T\)


Logical Disjunction

The disjunction connective defines the truth function $f^\lor$ as follows:

\(\ds \map {f^\lor} {\F, \F}\) \(=\) \(\ds \F\)
\(\ds \map {f^\lor} {\F, \T}\) \(=\) \(\ds \T\)
\(\ds \map {f^\lor} {\T, \F}\) \(=\) \(\ds \T\)
\(\ds \map {f^\lor} {\T, \T}\) \(=\) \(\ds \T\)


Conditional

The conditional connective defines the truth function $f^\to$ as follows:

\(\ds \map {f^\to} {\F, \F}\) \(=\) \(\ds \T\)
\(\ds \map {f^\to} {\F, \T}\) \(=\) \(\ds \T\)
\(\ds \map {f^\to} {\T, \F}\) \(=\) \(\ds \F\)
\(\ds \map {f^\to} {\T, \T}\) \(=\) \(\ds \T\)


Biconditional

The biconditional connective defines the truth function $f^\leftrightarrow$ as follows:

\(\ds \map {f^\leftrightarrow} {\F, \F}\) \(=\) \(\ds \T\)
\(\ds \map {f^\leftrightarrow} {\F, \T}\) \(=\) \(\ds \F\)
\(\ds \map {f^\leftrightarrow} {\T, \F}\) \(=\) \(\ds \F\)
\(\ds \map {f^\leftrightarrow} {\T, \T}\) \(=\) \(\ds \T\)


Exclusive Disjunction

The exclusive or connective defines the truth function $f^\oplus$ as follows:

\(\ds \map {f^\oplus} {\F, \F}\) \(=\) \(\ds \F\)
\(\ds \map {f^\oplus} {\F, \T}\) \(=\) \(\ds \T\)
\(\ds \map {f^\oplus} {\T, \F}\) \(=\) \(\ds \T\)
\(\ds \map {f^\oplus} {\T, \T}\) \(=\) \(\ds \F\)


Logical NAND

The NAND connective defines the truth function $f^\uparrow$ as follows:

\(\ds \map {f^\uparrow} {\F, \F}\) \(=\) \(\ds \T\)
\(\ds \map {f^\uparrow} {\F, \T}\) \(=\) \(\ds \T\)
\(\ds \map {f^\uparrow} {\T, \F}\) \(=\) \(\ds \T\)
\(\ds \map {f^\uparrow} {\T, \T}\) \(=\) \(\ds \F\)


Logical NOR

The NOR connective defines the truth function $f^\downarrow$ as follows:

\(\ds \map {f^\downarrow} {\F, \F}\) \(=\) \(\ds \T\)
\(\ds \map {f^\downarrow} {\F, \T}\) \(=\) \(\ds \F\)
\(\ds \map {f^\downarrow} {\T, \F}\) \(=\) \(\ds \F\)
\(\ds \map {f^\downarrow} {\T, \T}\) \(=\) \(\ds \F\)