theorem Th17: :: GFACIRC1:17

for x, y, z being set holds
( [<*x,y*>,and2] in InnerVertices (GFA0CarryStr (x,y,z)) & [<*y,z*>,and2] in InnerVertices (GFA0CarryStr (x,y,z)) & [<*z,x*>,and2] in InnerVertices (GFA0CarryStr (x,y,z)) & GFA0CarryOutput (x,y,z) in InnerVertices (GFA0CarryStr (x,y,z)) )