logic variable

programming A variable in a logic programming language

which is initially undefined ("unbound") but may get bound to

a value or another logic variable during unification of the

containing clause with the current goal. The value to which

it is bound may contain other variables which may themselves

be bound or unbound.

For example, when unifying the clause

sad(X) :- computer(X, ibmpc).

with the goal

sad(billgates).

the variable X will become bound to the atom "billgates"

yielding the new subgoal "computer(billgates, ibmpc)".

(1995-03-14)