Theorem r2al 2550

Description: Double restricted universal quantification. (Contributed by NM, 19-Nov-1995.)

Assertion

Ref	Expression
r2al	|- ( A. x e. A A. y e. B ph <-> A. x A. y ( ( x e. A /\ y e. B ) -> ph ) )

Distinct variable groups:   x, y   y, A

Allowed substitution hints:   ph( x, y)   A( x)   B( x, y)

Proof of Theorem r2al

Step	Hyp	Ref	Expression
1		nfcv 2373	. 2 |- F/_ y A
2	1	r2alf 2548	1 |- ( A. x e. A A. y e. B ph <-> A. x A. y ( ( x e. A /\ y e. B ) -> ph ) )

Syntax hints:   -> wi 4   /\ wa 104   <-> wb 105   A.wal 1395   e. wcel 2201   A.wral 2509

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 716  ax-5 1495  ax-7 1496  ax-gen 1497  ax-ie1 1541  ax-ie2 1542  ax-8 1552  ax-10 1553  ax-11 1554  ax-i12 1555  ax-bndl 1557  ax-4 1558  ax-17 1574  ax-i9 1578  ax-ial 1582  ax-i5r 1583  ax-ext 2212

This theorem depends on definitions:  df-bi 117  df-nf 1509  df-sb 1810  df-cleq 2223  df-clel 2226  df-nfc 2362  df-ral 2514

This theorem is referenced by:  r3al  2575  raliunxp  4873  codir  5127  qfto  5128  fununi  5400  dff13  5914  mpo2eqb  6136  qliftfun  6791  cnmpt12  15040  cnmpt22  15047