:: TOPMETR2 semantic presentation
theorem Th1: :: TOPMETR2:1
theorem Th2: :: TOPMETR2:2
Lemma2:
for b1, b2 being Function st b1 .: ((dom b1) /\ (dom b2)) c= rng b2 holds
(rng b1) \ (rng b2) c= rng (b1 +* b2)
theorem Th3: :: TOPMETR2:3
theorem Th4: :: TOPMETR2:4
theorem Th5: :: TOPMETR2:5
theorem Th6: :: TOPMETR2:6