scheme :: GFACIRC1:sch 2
1AryBooleUniq{ F₁( set ) -> Element of BOOLEAN } :

for f1, f2 being Function of (1 -tuples_on BOOLEAN),BOOLEAN st ( for x being Element of BOOLEAN holds f1 . <*x*> = F₁(x) ) & ( for x being Element of BOOLEAN holds f2 . <*x*> = F₁(x) ) holds
f1 = f2