theorem Th19:
  CongrLatt A is /\-inheriting
proof
  set E = EqRelLatt the Sorts of A;
  set C = CongrLatt A;
  now
    let B be Subset of C;
    reconsider d = "/\" (B,E) as MSCongruence of A by Th11;
    d in the carrier of C by MSUALG_5:def 6;
    hence "/\" (B,E) in the carrier of C;
  end;
  hence thesis by MSUALG_7:def 2;
end;
