Theorem univ 4617

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 3929	. . 3 |- ~P _V = _V
2	1	unieqi 3940	. 2 |- U. ~P _V = U. _V
3		unipw 4352	. 2 |- U. ~P _V = _V
4	2, 3	eqtr3i 2261	1 |- U. _V = _V

Syntax hints:   = wceq 1402   _Vcvv 2821   ~Pcpw 3685   U.cuni 3930

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 721  ax-5 1500  ax-7 1501  ax-gen 1502  ax-ie1 1546  ax-ie2 1547  ax-8 1557  ax-10 1558  ax-11 1559  ax-i12 1560  ax-bndl 1562  ax-4 1563  ax-17 1579  ax-i9 1583  ax-ial 1587  ax-i5r 1588  ax-14 2212  ax-ext 2220  ax-sep 4244  ax-pow 4306

This theorem depends on definitions:  df-bi 117  df-tru 1405  df-nf 1514  df-sb 1816  df-clab 2225  df-cleq 2231  df-clel 2234  df-nfc 2381  df-rex 2534  df-v 2823  df-in 3226  df-ss 3233  df-pw 3687  df-sn 3711  df-uni 3931

This theorem is referenced by: (None)