theorem
  m <= n & <%>E in B implies A c= A ^^ (B |^ (m, n)) & A c= (B |^ (m, n) ) ^^ A
proof
  assume m <= n & <%>E in B;
  then <%>E in B |^ (m, n) by Th33;
  hence thesis by FLANG_1:16;
end;
