
theorem ThCanFSIsMss:
  for A being finite set
  holds canFS A is ManySortedSet of Seg (card A)
proof
  let A be finite set;
  set f=canFS A;
  len f = card A by FINSEQ_1:93;
  then A1: dom f = Seg (card A) by FINSEQ_1:def 3;
  then reconsider f as (Seg (card A))-defined Function by RELAT_1:def 18;
  f is total by A1, PARTFUN1:def 2;
  hence canFS A is ManySortedSet of Seg (card A);
end;
