Availability:built-in
[ISO,det]retractall(+Head)All facts or clauses in the database for which the head
unifies with Head are removed. If all arguments of Head
are non-sharing variables (see is_most_general_term/1),
all clauses are removed without inspecting the clauses. Cleaning all
clauses of a dynamic predicate must use retractall/1
rather than abolish/1
as the latter completely wipes the predicate, including its properties.
If
Head refers to a predicate that is not defined, it is
implicitly created as a dynamic predicate. See also dynamic/1.89The
ISO standard only allows using dynamic/1
as a directive.