
theorem Th38:
  for x,b being non pair set holds InnerVertices BitCompStr(x,b) =
  {[<*x,b*>,xor2a],[<*x,b*>,and2a]}
proof
  let x,b be non pair set;
  set p = <*x,b*>;
  set S1 = CompStr(x,b);
  set S2 = IncrementStr(x,b);
  set S = BitCompStr(x,b);
A1: InnerVertices S1 = {[p,xor2a]} & InnerVertices S2 = {[p,and2a]} by
CIRCCOMB:42;
  InnerVertices S = (InnerVertices S1) \/ InnerVertices S2 by FACIRC_1:27
    .= {[p,xor2a], [p,and2a]} by A1,ENUMSET1:1;
  hence thesis;
end;
