Function: remlet (<prod>, <name>)
Function: remlet ()
Function: remlet (all)
Function: remlet (all, <name>) Deletes the substitution rule, <prod> -> repl, most recently defined by the
let function. If name is supplied the rule is deleted from the rule package name.
remlet(all) delete all substitution rules from the current rule package. If the name of a rule package is supplied, e.g.
remlet (all, <name>), the rule package <name> is also deleted.
If a substitution is to be changed using the same product,
remlet need not be called, just redefine the substitution using the same product (literally) with the
let function and the new replacement and/or predicate name. Should
remlet (<prod>) now be called the original substitution rule is revived.
remrule, which removes a rule defined by
(%o1) true (%i2)