reserve E, x, y, X for set;
reserve A, B, C for Subset of E^omega;
reserve a, b for Element of E^omega;
reserve i, k, l, kl, m, n, mn for Nat;

theorem
  m <= n & n > 0 implies (A*) |^ (m, n) = A*
proof
  assume that
A1: m <= n and
A2: n > 0;
  <%>E in A* by FLANG_1:48;
  hence (A*) |^ (m, n) = (A*) |^ n by A1,Th34
    .= A* by A2,FLANG_1:66;
end;
