
theorem Th21:
  for N being meet-continuous Lawson complete TopLattice, x
  being Element of N holds x"/\" is continuous
proof
  let N be meet-continuous Lawson complete TopLattice, x be Element of N;
  for X being non empty Subset of N holds x"/\" preserves_inf_of X by
YELLOW13:11;
  hence thesis by WAYBEL21:45;
end;
