theorem Th126: :: GFACIRC1:126
for x, y, z being set st z <> [<*x,y*>,xor2] holds
for s being State of (GFA3AdderCirc (x,y,z))
for a1, a2, a3 being Element of BOOLEAN st a1 = s . x & a2 = s . y & a3 = s . z holds
(Following (s,2)) . (GFA3AdderOutput (x,y,z)) = 'not' ((('not' a1) 'xor' ('not' a2)) 'xor' ('not' a3))