"all clauses of a predicate with functor Functor and arity Arity"
The "functor" is the tuple (predicate name, arity). That tuple can be given as a predicate indicator which is a program element that looks like this:
So the text should say:
"all clauses of the predicate designated by given predicate indicator
"This is odd" is a nice way of saying "the standard is wrong". That the standard can be wrong is hardly surprising...