Definition:Logical Connective/Unary
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Definition
A unary logical connective is a logical connective whose effect on its compound statement is determined by the truth value of one substatement.
In standard Aristotelian logic, there are four of these.
The only non-trivial one is logical not, as shown on Unary Truth Functions.
Also defined as
Some treatments do not consider a unary connective to be a logical connective as such, because it does not actually "connect" anything.
However, this is a trivial point which can serve only to confuse.
Also known as
A unary logical connective is also known as a one-place connective.
Some sources just call it a unary connective.
Also see
- Results about logical connectives can be found here.
Linguistic Note
The word unary is pronounced yoo-nary.
Hence when the indefinite article precedes it, the form is (for example) a unary operation.
Sources
- 1980: D.J. O'Connor and Betty Powell: Elementary Logic ... (previous) ... (next): $\S \text{I}: 2$: Logical Constants $(1)$