Theorem fvdiagfn 6941

Description: Functionality of the diagonal map. (Contributed by Stefan O'Rear, 24-Jan-2015.)

Hypothesis

Ref	Expression
fdiagfn.f	|- F = ( x e. B |-> ( I X. { x } ) )

Assertion

Ref	Expression
fvdiagfn	|- ( ( I e. W /\ X e. B ) -> ( F ` X ) = ( I X. { X } ) )

Distinct variable groups:   x, B   x, I   x, W   x, X

Allowed substitution hint:   F( x)

Proof of Theorem fvdiagfn

Step	Hyp	Ref	Expression
1		simpr 110	. 2 |- ( ( I e. W /\ X e. B ) -> X e. B )
2		snexg 4302	. . 3 |- ( X e. B -> { X } e. _V )
3		xpexg 4869	. . 3 |- ( ( I e. W /\ { X } e. _V ) -> ( I X. { X } ) e. _V )
4	2, 3	sylan2 286	. 2 |- ( ( I e. W /\ X e. B ) -> ( I X. { X } ) e. _V )
5		sneq 3705	. . . 4 |- ( x = X -> { x } = { X } )
6	5	xpeq2d 4778	. . 3 |- ( x = X -> ( I X. { x } ) = ( I X. { X } ) )
7		fdiagfn.f	. . 3 |- F = ( x e. B |-> ( I X. { x } ) )
8	6, 7	fvmptg 5758	. 2 |- ( ( X e. B /\ ( I X. { X } ) e. _V ) -> ( F ` X ) = ( I X. { X } ) )
9	1, 4, 8	syl2anc 411	1 |- ( ( I e. W /\ X e. B ) -> ( F ` X ) = ( I X. { X } ) )

Syntax hints:   -> wi 4   /\ wa 104   = wceq 1398   e. wcel 2205   _Vcvv 2815   {csn 3694   |-> cmpt 4176   X. cxp 4752   ` cfv 5357

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 717  ax-5 1496  ax-7 1497  ax-gen 1498  ax-ie1 1542  ax-ie2 1543  ax-8 1553  ax-10 1554  ax-11 1555  ax-i12 1556  ax-bndl 1558  ax-4 1559  ax-17 1575  ax-i9 1579  ax-ial 1583  ax-i5r 1584  ax-13 2207  ax-14 2208  ax-ext 2216  ax-sep 4233  ax-pow 4292  ax-pr 4327  ax-un 4559

This theorem depends on definitions:  df-bi 117  df-3an 1007  df-tru 1401  df-nf 1510  df-sb 1812  df-eu 2085  df-mo 2086  df-clab 2221  df-cleq 2227  df-clel 2230  df-nfc 2375  df-ral 2527  df-rex 2528  df-v 2817  df-sbc 3046  df-un 3218  df-in 3220  df-ss 3227  df-pw 3676  df-sn 3700  df-pr 3701  df-op 3703  df-uni 3920  df-br 4115  df-opab 4177  df-mpt 4178  df-id 4419  df-xp 4760  df-rel 4761  df-cnv 4762  df-co 4763  df-dm 4764  df-iota 5317  df-fun 5359  df-fv 5365

This theorem is referenced by: (None)