scheme :: MODELC_1:sch 2
Func1EX{ F₁() -> non empty set , F₂() -> Function of F₁(),BOOLEAN, F₃( object , Function of F₁(),BOOLEAN) -> boolean object } :

ex g being set st
( g in ModelSP F₁() & ( for s being set st s in F₁() holds
( F₃(s,F₂()) = TRUE iff (Fid (g,F₁())) . s = TRUE ) ) )