Note that PredSpec is specified in the format Name/Arity and may be specified with Name as an atom or variable and/or Arity as an integer or variable.
Success:
   current_functor(findall/N).
   current_functor(N/4).
   current_functor((',')/2).
   [eclipse]: current_functor(X).
   X = '' / 0     More? (;)
   X = findall / 0     More? (;)
   X = findall / 3     More? (;)
   X = at_eof_handler / 0     More? (;)    % RETURN pressed
   yes.
   [eclipse]:
Fail:
   current_functor(myfunctor/100).
Error:
   current_functor(abc)           Error 5.
   current_functor(man(1)).       Error 5.