set f1 = nor2 ;
set f2 = nor2 ;
set f3 = nor2 ;
let x, y, z be set ; ( x <> [<*y,z*>,nor2] & y <> [<*z,x*>,nor2] & z <> [<*x,y*>,nor2] implies ( x in InputVertices (GFA3CarryStr (x,y,z)) & y in InputVertices (GFA3CarryStr (x,y,z)) & z in InputVertices (GFA3CarryStr (x,y,z)) ) )
assume
( x <> [<*y,z*>,nor2] & y <> [<*z,x*>,nor2] & z <> [<*x,y*>,nor2] )
; ( x in InputVertices (GFA3CarryStr (x,y,z)) & y in InputVertices (GFA3CarryStr (x,y,z)) & z in InputVertices (GFA3CarryStr (x,y,z)) )
then
InputVertices (GFA3CarryStr (x,y,z)) = {x,y,z}
by Th109;
hence
( x in InputVertices (GFA3CarryStr (x,y,z)) & y in InputVertices (GFA3CarryStr (x,y,z)) & z in InputVertices (GFA3CarryStr (x,y,z)) )
by ENUMSET1:def 1; verum