Theorem ressn 5224

Description: Restriction of a class to a singleton. (Contributed by Mario Carneiro, 28-Dec-2014.)

Assertion

Ref	Expression
ressn	|- ( A |` { B } ) = ( { B } X. ( A " { B } ) )

Proof of Theorem ressn

Dummy variables x y are mutually distinct and distinct from all other variables.

Step	Hyp	Ref	Expression
1		relres 4988	. 2 |- Rel ( A |` { B } )
2		relxp 4785	. 2 |- Rel ( { B } X. ( A " { B } ) )
3		ancom 266	. . . 4 |- ( ( <. x , y >. e. A /\ x e. { B } ) <-> ( x e. { B } /\ <. x , y >. e. A ) )
4		vex 2775	. . . . . . 7 |- x e. _V
5		vex 2775	. . . . . . 7 |- y e. _V
6	4, 5	elimasn 5050	. . . . . 6 |- ( y e. ( A " { x } ) <-> <. x , y >. e. A )
7		elsni 3651	. . . . . . . . 9 |- ( x e. { B } -> x = B )
8	7	sneqd 3646	. . . . . . . 8 |- ( x e. { B } -> { x } = { B } )
9	8	imaeq2d 5023	. . . . . . 7 |- ( x e. { B } -> ( A " { x } ) = ( A " { B } ) )
10	9	eleq2d 2275	. . . . . 6 |- ( x e. { B } -> ( y e. ( A " { x } ) <-> y e. ( A " { B } ) ) )
11	6, 10	bitr3id 194	. . . . 5 |- ( x e. { B } -> ( <. x , y >. e. A <-> y e. ( A " { B } ) ) )
12	11	pm5.32i 454	. . . 4 |- ( ( x e. { B } /\ <. x , y >. e. A ) <-> ( x e. { B } /\ y e. ( A " { B } ) ) )
13	3, 12	bitri 184	. . 3 |- ( ( <. x , y >. e. A /\ x e. { B } ) <-> ( x e. { B } /\ y e. ( A " { B } ) ) )
14	5	opelres 4965	. . 3 |- ( <. x , y >. e. ( A |` { B } ) <-> ( <. x , y >. e. A /\ x e. { B } ) )
15		opelxp 4706	. . 3 |- ( <. x , y >. e. ( { B } X. ( A " { B } ) ) <-> ( x e. { B } /\ y e. ( A " { B } ) ) )
16	13, 14, 15	3bitr4i 212	. 2 |- ( <. x , y >. e. ( A |` { B } ) <-> <. x , y >. e. ( { B } X. ( A " { B } ) ) )
17	1, 2, 16	eqrelriiv 4770	1 |- ( A |` { B } ) = ( { B } X. ( A " { B } ) )

Syntax hints:   /\ wa 104   = wceq 1373   e. wcel 2176   {csn 3633   <.cop 3636   X. cxp 4674   |` cres 4678   "cima 4679

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 711  ax-5 1470  ax-7 1471  ax-gen 1472  ax-ie1 1516  ax-ie2 1517  ax-8 1527  ax-10 1528  ax-11 1529  ax-i12 1530  ax-bndl 1532  ax-4 1533  ax-17 1549  ax-i9 1553  ax-ial 1557  ax-i5r 1558  ax-14 2179  ax-ext 2187  ax-sep 4163  ax-pow 4219  ax-pr 4254

This theorem depends on definitions:  df-bi 117  df-3an 983  df-tru 1376  df-nf 1484  df-sb 1786  df-eu 2057  df-mo 2058  df-clab 2192  df-cleq 2198  df-clel 2201  df-nfc 2337  df-ral 2489  df-rex 2490  df-v 2774  df-sbc 2999  df-un 3170  df-in 3172  df-ss 3179  df-pw 3618  df-sn 3639  df-pr 3640  df-op 3642  df-br 4046  df-opab 4107  df-xp 4682  df-rel 4683  df-cnv 4684  df-dm 4686  df-rn 4687  df-res 4688  df-ima 4689

This theorem is referenced by: (None)