
theorem Th27:
  for x,b being non pair set holds the carrier of CompStr(x,b) = {
  x,b} \/ {[<*x,b*>,xor2a]}
proof
  let x,b be non pair set;
  set p = <*x,b*>;
  rng p = {x,b} by FINSEQ_2:127;
  hence thesis by CIRCCOMB:def 6;
end;
