let x, y, z be set ; ( x in the carrier of (BitGFA2Str x,y,z) & y in the carrier of (BitGFA2Str x,y,z) & z in the carrier of (BitGFA2Str x,y,z) & [<*x,y*>,xor2c ] in the carrier of (BitGFA2Str x,y,z) & [<*[<*x,y*>,xor2c ],z*>,xor2c ] in the carrier of (BitGFA2Str x,y,z) & [<*x,y*>,and2a ] in the carrier of (BitGFA2Str x,y,z) & [<*y,z*>,and2c ] in the carrier of (BitGFA2Str x,y,z) & [<*z,x*>,and2b ] in the carrier of (BitGFA2Str x,y,z) & [<*[<*x,y*>,and2a ],[<*y,z*>,and2c ],[<*z,x*>,and2b ]*>,nor3 ] in the carrier of (BitGFA2Str x,y,z) )
set f1 = and2a ;
set f2 = and2c ;
set f3 = and2b ;
set f4 = nor3 ;
set f0 = xor2c ;
set xy = [<*x,y*>,and2a ];
set yz = [<*y,z*>,and2c ];
set zx = [<*z,x*>,and2b ];
set xyz = [<*[<*x,y*>,and2a ],[<*y,z*>,and2c ],[<*z,x*>,and2b ]*>,nor3 ];
set S1 = GFA2AdderStr x,y,z;
set S2 = GFA2CarryStr x,y,z;
A1:
( x in the carrier of (GFA2AdderStr x,y,z) & y in the carrier of (GFA2AdderStr x,y,z) )
by FACIRC_1:60;
A2:
( z in the carrier of (GFA2AdderStr x,y,z) & [<*x,y*>,xor2c ] in the carrier of (GFA2AdderStr x,y,z) )
by FACIRC_1:60, FACIRC_1:61;
A3:
[<*[<*x,y*>,and2a ],[<*y,z*>,and2c ],[<*z,x*>,and2b ]*>,nor3 ] in the carrier of (GFA2CarryStr x,y,z)
by Th92;
A4:
( [<*y,z*>,and2c ] in the carrier of (GFA2CarryStr x,y,z) & [<*z,x*>,and2b ] in the carrier of (GFA2CarryStr x,y,z) )
by Th92;
( [<*[<*x,y*>,xor2c ],z*>,xor2c ] in the carrier of (GFA2AdderStr x,y,z) & [<*x,y*>,and2a ] in the carrier of (GFA2CarryStr x,y,z) )
by Th92, FACIRC_1:61;
hence
( x in the carrier of (BitGFA2Str x,y,z) & y in the carrier of (BitGFA2Str x,y,z) & z in the carrier of (BitGFA2Str x,y,z) & [<*x,y*>,xor2c ] in the carrier of (BitGFA2Str x,y,z) & [<*[<*x,y*>,xor2c ],z*>,xor2c ] in the carrier of (BitGFA2Str x,y,z) & [<*x,y*>,and2a ] in the carrier of (BitGFA2Str x,y,z) & [<*y,z*>,and2c ] in the carrier of (BitGFA2Str x,y,z) & [<*z,x*>,and2b ] in the carrier of (BitGFA2Str x,y,z) & [<*[<*x,y*>,and2a ],[<*y,z*>,and2c ],[<*z,x*>,and2b ]*>,nor3 ] in the carrier of (BitGFA2Str x,y,z) )
by A1, A2, A4, A3, FACIRC_1:20; verum