theorem Th116: :: GFACIRC1:116

for x, y, z being set
for s being State of (GFA3CarryCirc (x,y,z))
for a1, a2, a3 being Element of BOOLEAN st a1 = s . [<*x,y*>,nor2] & a2 = s . [<*y,z*>,nor2] & a3 = s . [<*z,x*>,nor2] holds
(Following s) . (GFA3CarryOutput (x,y,z)) = 'not' ((a1 'or' a2) 'or' a3)