Clears a blackboard.
bb_clear/2 removes all elements from the inner blackboard identified with Key, belonging to the outer blackboard Board. This predicate is equivalent to:
bb_get(Board, Key, SubBoard) -> bb_clear(SubBoard) ; true
Board blackboard Key ground term
bb_create(SparseArray),
bb_put(SparseArray, 7, 563, 10),
% elements: 7 -> { 365 -> 10 }
bb_put(SparseArray, 7, 43, 15),
% elements: 7 -> { 365 -> 10, 43 -> 15 }
bb_put(SparseArray, 365, 5, 20),
% elements: 7 -> { 365 -> 10, 43 -> 15 }, 365 -> { 5 -> 20 }
bb_clear(SparseArray, 7)
% elements: 7 -> {} , 365 -> { 5 -> 20 }
This predicate is not part of the ISO-Prolog Standard.