Theorem ssxp1 4975

Description: Cross product subset cancellation. (Contributed by Jim Kingdon, 14-Dec-2018.)

Assertion

Ref	Expression
ssxp1	|- ( E. x x e. C -> ( ( A X. C ) C_ ( B X. C ) <-> A C_ B ) )

Distinct variable group:   x, C

Allowed substitution hints:   A( x)   B( x)

Proof of Theorem ssxp1

Step	Hyp	Ref	Expression
1		dmxpm 4759	. . . . . 6 |- ( E. x x e. C -> dom ( A X. C ) = A )
2	1	adantr 274	. . . . 5 |- ( ( E. x x e. C /\ ( A X. C ) C_ ( B X. C ) ) -> dom ( A X. C ) = A )
3		dmss 4738	. . . . . 6 |- ( ( A X. C ) C_ ( B X. C ) -> dom ( A X. C ) C_ dom ( B X. C ) )
4	3	adantl 275	. . . . 5 |- ( ( E. x x e. C /\ ( A X. C ) C_ ( B X. C ) ) -> dom ( A X. C ) C_ dom ( B X. C ) )
5	2, 4	eqsstrrd 3134	. . . 4 |- ( ( E. x x e. C /\ ( A X. C ) C_ ( B X. C ) ) -> A C_ dom ( B X. C ) )
6		dmxpss 4969	. . . 4 |- dom ( B X. C ) C_ B
7	5, 6	sstrdi 3109	. . 3 |- ( ( E. x x e. C /\ ( A X. C ) C_ ( B X. C ) ) -> A C_ B )
8	7	ex 114	. 2 |- ( E. x x e. C -> ( ( A X. C ) C_ ( B X. C ) -> A C_ B ) )
9		xpss1 4649	. 2 |- ( A C_ B -> ( A X. C ) C_ ( B X. C ) )
10	8, 9	impbid1 141	1 |- ( E. x x e. C -> ( ( A X. C ) C_ ( B X. C ) <-> A C_ B ) )

Syntax hints:   -> wi 4   /\ wa 103   <-> wb 104   = wceq 1331   E.wex 1468   e. wcel 1480   C_ wss 3071   X. cxp 4537   dom cdm 4539

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-io 698  ax-5 1423  ax-7 1424  ax-gen 1425  ax-ie1 1469  ax-ie2 1470  ax-8 1482  ax-10 1483  ax-11 1484  ax-i12 1485  ax-bndl 1486  ax-4 1487  ax-14 1492  ax-17 1506  ax-i9 1510  ax-ial 1514  ax-i5r 1515  ax-ext 2121  ax-sep 4046  ax-pow 4098  ax-pr 4131

This theorem depends on definitions:  df-bi 116  df-3an 964  df-tru 1334  df-nf 1437  df-sb 1736  df-eu 2002  df-mo 2003  df-clab 2126  df-cleq 2132  df-clel 2135  df-nfc 2270  df-ral 2421  df-rex 2422  df-v 2688  df-un 3075  df-in 3077  df-ss 3084  df-pw 3512  df-sn 3533  df-pr 3534  df-op 3536  df-br 3930  df-opab 3990  df-xp 4545  df-dm 4549

This theorem is referenced by:  xpcan2m  4979