Definition:Functionally Complete

Definition
Let $S$ be a set of truth functions.

Then $S$ is functionally complete if all possible truth functions can be obtained by suitable compositions of:


 * elements of $S$; and
 * the diagonal mapping $\Delta: \mathbb B \to \mathbb B^2$ on the set of truth values $\mathbb B$.

Also known as
A functionally complete set is also known as expressively adequate.

Also see

 * Definition:Sheffer Operator