
theorem Th6: :: COROLLARY 4.10.
  for L be algebraic lower-bounded LATTICE for S be CLSubFrame of L
  holds S is algebraic
proof
  let L be algebraic lower-bounded LATTICE;
  let S be CLSubFrame of L;
  the RelStr of S = Image closure_op S by WAYBEL10:18;
  then (the RelStr of S) is algebraic by WAYBEL_8:24;
  hence thesis by WAYBEL_8:17;
end;
