Theorem univ 4579

Description: The union of the universe is the universe. Exercise 4.12(c) of [Mendelson] p. 235. (Contributed by NM, 14-Sep-2003.)

Assertion

Ref	Expression
univ	|- U. _V = _V

Proof of Theorem univ

Step	Hyp	Ref	Expression
1		pwv 3897	. . 3 |- ~P _V = _V
2	1	unieqi 3908	. 2 |- U. ~P _V = U. _V
3		unipw 4315	. 2 |- U. ~P _V = _V
4	2, 3	eqtr3i 2254	1 |- U. _V = _V

Syntax hints:   = wceq 1398   _Vcvv 2803   ~Pcpw 3656   U.cuni 3898

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-io 717  ax-5 1496  ax-7 1497  ax-gen 1498  ax-ie1 1542  ax-ie2 1543  ax-8 1553  ax-10 1554  ax-11 1555  ax-i12 1556  ax-bndl 1558  ax-4 1559  ax-17 1575  ax-i9 1579  ax-ial 1583  ax-i5r 1584  ax-14 2205  ax-ext 2213  ax-sep 4212  ax-pow 4270

This theorem depends on definitions:  df-bi 117  df-tru 1401  df-nf 1510  df-sb 1811  df-clab 2218  df-cleq 2224  df-clel 2227  df-nfc 2364  df-rex 2517  df-v 2805  df-in 3207  df-ss 3214  df-pw 3658  df-sn 3679  df-uni 3899

This theorem is referenced by: (None)