let x, y, c be non pair object ; InnerVertices (BitAdderWithOverflowStr (x,y,c)) = ({[<*x,y*>,'xor'],(2GatesCircOutput (x,y,c,'xor'))} \/ {[<*x,y*>,'&'],[<*y,c*>,'&'],[<*c,x*>,'&']}) \/ {(MajorityOutput (x,y,c))}
set S1 = 2GatesCircStr (x,y,c,'xor');
set S2 = MajorityStr (x,y,c);
A1:
InnerVertices (MajorityStr (x,y,c)) = {[<*x,y*>,'&'],[<*y,c*>,'&'],[<*c,x*>,'&']} \/ {(MajorityOutput (x,y,c))}
by Th75;
( ({[<*x,y*>,'xor'],(2GatesCircOutput (x,y,c,'xor'))} \/ {[<*x,y*>,'&'],[<*y,c*>,'&'],[<*c,x*>,'&']}) \/ {(MajorityOutput (x,y,c))} = {[<*x,y*>,'xor'],(2GatesCircOutput (x,y,c,'xor'))} \/ ({[<*x,y*>,'&'],[<*y,c*>,'&'],[<*c,x*>,'&']} \/ {(MajorityOutput (x,y,c))}) & InnerVertices (2GatesCircStr (x,y,c,'xor')) = {[<*x,y*>,'xor'],(2GatesCircOutput (x,y,c,'xor'))} )
by Th56, XBOOLE_1:4;
hence
InnerVertices (BitAdderWithOverflowStr (x,y,c)) = ({[<*x,y*>,'xor'],(2GatesCircOutput (x,y,c,'xor'))} \/ {[<*x,y*>,'&'],[<*y,c*>,'&'],[<*c,x*>,'&']}) \/ {(MajorityOutput (x,y,c))}
by A1, Th27; verum