Theorem prneimg 3774

Description: Two pairs are not equal if at least one element of the first pair is not contained in the second pair. (Contributed by Alexander van der Vekens, 13-Aug-2017.)

Assertion

Ref	Expression
prneimg	|- ( ( ( A e. U /\ B e. V ) /\ ( C e. X /\ D e. Y ) ) -> ( ( ( A =/= C /\ A =/= D ) \/ ( B =/= C /\ B =/= D ) ) -> { A , B } =/= { C , D } ) )

Proof of Theorem prneimg

Step	Hyp	Ref	Expression
1		preq12bg 3773	. . . . 5 |- ( ( ( A e. U /\ B e. V ) /\ ( C e. X /\ D e. Y ) ) -> ( { A , B } = { C , D } <-> ( ( A = C /\ B = D ) \/ ( A = D /\ B = C ) ) ) )
2		orddi 820	. . . . . 6 |- ( ( ( A = C /\ B = D ) \/ ( A = D /\ B = C ) ) <-> ( ( ( A = C \/ A = D ) /\ ( A = C \/ B = C ) ) /\ ( ( B = D \/ A = D ) /\ ( B = D \/ B = C ) ) ) )
3		simpll 527	. . . . . . 7 |- ( ( ( ( A = C \/ A = D ) /\ ( A = C \/ B = C ) ) /\ ( ( B = D \/ A = D ) /\ ( B = D \/ B = C ) ) ) -> ( A = C \/ A = D ) )
4		pm1.4 727	. . . . . . . 8 |- ( ( B = D \/ B = C ) -> ( B = C \/ B = D ) )
5	4	ad2antll 491	. . . . . . 7 |- ( ( ( ( A = C \/ A = D ) /\ ( A = C \/ B = C ) ) /\ ( ( B = D \/ A = D ) /\ ( B = D \/ B = C ) ) ) -> ( B = C \/ B = D ) )
6	3, 5	jca 306	. . . . . 6 |- ( ( ( ( A = C \/ A = D ) /\ ( A = C \/ B = C ) ) /\ ( ( B = D \/ A = D ) /\ ( B = D \/ B = C ) ) ) -> ( ( A = C \/ A = D ) /\ ( B = C \/ B = D ) ) )
7	2, 6	sylbi 121	. . . . 5 |- ( ( ( A = C /\ B = D ) \/ ( A = D /\ B = C ) ) -> ( ( A = C \/ A = D ) /\ ( B = C \/ B = D ) ) )
8	1, 7	syl6bi 163	. . . 4 |- ( ( ( A e. U /\ B e. V ) /\ ( C e. X /\ D e. Y ) ) -> ( { A , B } = { C , D } -> ( ( A = C \/ A = D ) /\ ( B = C \/ B = D ) ) ) )
9		oranim 781	. . . . . 6 |- ( ( A = C \/ A = D ) -> -. ( -. A = C /\ -. A = D ) )
10		df-ne 2348	. . . . . . 7 |- ( A =/= C <-> -. A = C )
11		df-ne 2348	. . . . . . 7 |- ( A =/= D <-> -. A = D )
12	10, 11	anbi12i 460	. . . . . 6 |- ( ( A =/= C /\ A =/= D ) <-> ( -. A = C /\ -. A = D ) )
13	9, 12	sylnibr 677	. . . . 5 |- ( ( A = C \/ A = D ) -> -. ( A =/= C /\ A =/= D ) )
14		oranim 781	. . . . . 6 |- ( ( B = C \/ B = D ) -> -. ( -. B = C /\ -. B = D ) )
15		df-ne 2348	. . . . . . 7 |- ( B =/= C <-> -. B = C )
16		df-ne 2348	. . . . . . 7 |- ( B =/= D <-> -. B = D )
17	15, 16	anbi12i 460	. . . . . 6 |- ( ( B =/= C /\ B =/= D ) <-> ( -. B = C /\ -. B = D ) )
18	14, 17	sylnibr 677	. . . . 5 |- ( ( B = C \/ B = D ) -> -. ( B =/= C /\ B =/= D ) )
19	13, 18	anim12i 338	. . . 4 |- ( ( ( A = C \/ A = D ) /\ ( B = C \/ B = D ) ) -> ( -. ( A =/= C /\ A =/= D ) /\ -. ( B =/= C /\ B =/= D ) ) )
20	8, 19	syl6 33	. . 3 |- ( ( ( A e. U /\ B e. V ) /\ ( C e. X /\ D e. Y ) ) -> ( { A , B } = { C , D } -> ( -. ( A =/= C /\ A =/= D ) /\ -. ( B =/= C /\ B =/= D ) ) ) )
21		pm4.56 780	. . 3 |- ( ( -. ( A =/= C /\ A =/= D ) /\ -. ( B =/= C /\ B =/= D ) ) <-> -. ( ( A =/= C /\ A =/= D ) \/ ( B =/= C /\ B =/= D ) ) )
22	20, 21	syl6ib 161	. 2 |- ( ( ( A e. U /\ B e. V ) /\ ( C e. X /\ D e. Y ) ) -> ( { A , B } = { C , D } -> -. ( ( A =/= C /\ A =/= D ) \/ ( B =/= C /\ B =/= D ) ) ) )
23	22	necon2ad 2404	1 |- ( ( ( A e. U /\ B e. V ) /\ ( C e. X /\ D e. Y ) ) -> ( ( ( A =/= C /\ A =/= D ) \/ ( B =/= C /\ B =/= D ) ) -> { A , B } =/= { C , D } ) )

Syntax hints:   -. wn 3   -> wi 4   /\ wa 104   \/ wo 708   = wceq 1353   e. wcel 2148   =/= wne 2347   {cpr 3593

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-in1 614  ax-in2 615  ax-io 709  ax-5 1447  ax-7 1448  ax-gen 1449  ax-ie1 1493  ax-ie2 1494  ax-8 1504  ax-10 1505  ax-11 1506  ax-i12 1507  ax-bndl 1509  ax-4 1510  ax-17 1526  ax-i9 1530  ax-ial 1534  ax-i5r 1535  ax-ext 2159

This theorem depends on definitions:  df-bi 117  df-3an 980  df-tru 1356  df-nf 1461  df-sb 1763  df-clab 2164  df-cleq 2170  df-clel 2173  df-nfc 2308  df-ne 2348  df-v 2739  df-un 3133  df-sn 3598  df-pr 3599

This theorem is referenced by: (None)