retract

Tries to delete the first clause in this theory unifying against the given clause, returning a RetractResult.Success wrapping the resulting Theory and the removed clause, or a RetractResult.Failure wrapping this same theory if no clause matched.

Tries to delete, from this theory, one clause unifying against each of the given clauses patterns.

See also

Tries to delete a clause whose head unifies against the given head; equivalent to retract(Rule.of(head, _))