reserve n for Element of NAT,
  p,q,r,s for Element of HP-WFF;
reserve V for SetValuation;
reserve P for Permutation of V;

theorem Th32:
  Perm(P,VERUM) = id SetVal(V,VERUM)
proof
  thus Perm(P,VERUM) = id 1 by Def5
    .= id SetVal(V,VERUM) by Def2;
end;
