logic variable

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)