Removes procedures from the Prolog database.
Removes all procedures specified.
After this command is executed the current program functions as if
the named procedures had never existed. That is, in addition to removing all
the clauses for each specified procedure,
abolish removes any properties
that the procedure might have had, such as being dynamic or multifile.
You may abolish any of your own procedures, regardless of whether they are dynamic, static, compiled, interpreted, or foreign. You cannot abolish built-in procedures.
It is important to note that
erase/1 can only remove dynamic predicates. They cannot remove
the predicates properties (such as being dynamic or multifile) from
abolish[1,2], on the other hand, can remove both static
and dynamic predicates. It removes the clauses of the
predicates and its properties.
The procedures that are abolished do not become invisible to a currently running procedure. See ref-mdb-exa for an example illustrating this point.
Space occupied by abolished procedures is reclaimed. The space occupied by the procedures is reclaimed.
Procedures must be defined in the source module before they can be abolished. An attempt to abolish a procedure that is imported into the source module will cause a permission error. Using a module prefix, M:, clauses in any module may be abolished.
Abolishing a foreign procedure destroys only the link between that Prolog procedure and the associated foreign code. The foreign code that was loaded remains in memory. This is necessary because Prolog cannot tell which subsequently-loaded foreign files may have links to the foreign code. The Prolog part of the foreign procedure is destroyed and reclaimed.
Specifying an undefined procedure is not an error.
abolish/2 is an obsolete special case of
maintained to provide compatibility with DEC-10 Prolog, C Prolog, and earlier
versions of Quintus Prolog.