:: Some Facts about Union of Two Functions and Continuity of Union of Functions
:: by Yatsuka Nakamura and Agata Darmochwa{\l}
::
:: Received November 21, 1991
:: Copyright (c) 1991 Association of Mizar Users
:: TOPMETR2 semantic presentation
theorem Th1: :: TOPMETR2:1
theorem :: TOPMETR2:2
Lm1:
for f, g being Function st f .: ((dom f) /\ (dom g)) c= rng g holds
(rng f) \ (rng g) c= rng (f +* g)
theorem :: TOPMETR2:3
theorem Th4: :: TOPMETR2:4
theorem :: TOPMETR2:5
theorem :: TOPMETR2:6