Definition:Logical Connective/Unary

From ProofWiki
Jump to navigation Jump to search


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.