theorem Th18: :: FTACELL1:18

for ap, bm, cp, dm being non pair set
for cin being set st cin <> [<*dm,(GFA1AdderOutput (ap,bm,cp))*>,nor2] & not cin in InnerVertices (BitGFA1Str (ap,bm,cp)) holds
for s being State of (BitFTA1Circ (ap,bm,cp,dm,cin))
for a1, a2, a3, a4, a5 being Element of BOOLEAN st a1 = s . ap & a2 = s . bm & a3 = s . cp & a4 = s . dm & a5 = s . cin holds
( (Following (s,2)) . (GFA1AdderOutput (ap,bm,cp)) = 'not' ((a1 'xor' ('not' a2)) 'xor' a3) & (Following (s,2)) . ap = a1 & (Following (s,2)) . bm = a2 & (Following (s,2)) . cp = a3 & (Following (s,2)) . dm = a4 & (Following (s,2)) . cin = a5 )