let x, y, c be set ; for f being Function of (2 -tuples_on BOOLEAN ),BOOLEAN holds InnerVertices (2GatesCircStr x,y,c,f) = {[<*x,y*>,f],(2GatesCircOutput x,y,c,f)}
let f be Function of (2 -tuples_on BOOLEAN ),BOOLEAN ; InnerVertices (2GatesCircStr x,y,c,f) = {[<*x,y*>,f],(2GatesCircOutput x,y,c,f)}
set p = <*[<*x,y*>,f],c*>;
set S1 = 1GateCircStr <*x,y*>,f;
set S2 = 1GateCircStr <*[<*x,y*>,f],c*>,f;
set S = 2GatesCircStr x,y,c,f;
1GateCircStr <*x,y*>,f tolerates 1GateCircStr <*[<*x,y*>,f],c*>,f
by CIRCCOMB:51;
hence InnerVertices (2GatesCircStr x,y,c,f) =
(InnerVertices (1GateCircStr <*x,y*>,f)) \/ (InnerVertices (1GateCircStr <*[<*x,y*>,f],c*>,f))
by CIRCCOMB:15
.=
{[<*x,y*>,f]} \/ (InnerVertices (1GateCircStr <*[<*x,y*>,f],c*>,f))
by CIRCCOMB:49
.=
{[<*x,y*>,f]} \/ {[<*[<*x,y*>,f],c*>,f]}
by CIRCCOMB:49
.=
{[<*x,y*>,f],(2GatesCircOutput x,y,c,f)}
by ENUMSET1:41
;
verum