theorem
  B <> {} & f|B = g|B implies FinMeet(B,f) = FinMeet(B,g)
proof
  reconsider f9 = f, g9 = g as Function of A, the carrier of L.:;
A1: FinMeet(B,f) = FinJoin(B,f9) & FinMeet(B,g) = FinJoin(B,g9);
  assume B <> {} & f|B = g|B;
  hence thesis by A1,Th34;
end;
