
theorem Th40:
  for x,b being non pair set holds InputVertices BitCompStr(x,b) = {x,b}
proof
  let x,b be non pair set;
  set S1 = CompStr(x,b);
  set S2 = IncrementStr(x,b);
  set S = BitCompStr(x,b);
A1: InputVertices S1 = {x,b} & InputVertices S2 = {x,b} by FACIRC_1:40;
  InnerVertices S1 is Relation & InnerVertices S2 is Relation by FACIRC_1:38;
  then InputVertices S = {x,b} \/ {x,b} by A1,FACIRC_1:7
    .= {x,b};
  hence thesis;
end;
