Connective Glossary
Definition
A connective is an expression which applies to a specific number of sentences of a language to form a longer sentence of the same language in which the original(s) function as parts.
Comments
In elementary logic we are concerned mainly with truth-functional connectives. Most connectives in natural languages are not truth-functional. Their logic can be investigated, though in many cases it is not particularly interesting or useful to do so.
We allow the case of 0-ary connectives which form sentences without needing to apply to anything. The prominent example in standard logic is the absurd constant '⊥'.
Examples
- In the formal language of logic, ⊥ is a nullary connective, NOT is a unary connective, and AND, OR, IMP and IFF are all binary connectives.
- In English, unary connectives include necessarily, possibly, tomorrow and it is morally unacceptable that. Binary ones include because and until.