scheme :: HILB10_3:sch 2
Eq{ F1() -> Nat, P1[ object ], P2[ object ] } :
{ p where p is F1() -element XFinSequence of NAT : P1[p] } = { q where q is F1() -element XFinSequence of NAT : P2[q] }
provided
A1: for p being F1() -element XFinSequence of NAT holds
( P1[p] iff P2[p] )