Theorem fressnfv 3838

Description: The value of a function restricted to a singleton.

Assertion

Ref	Expression
fressnfv	|- ((F Fn A /\ B e. A) -> ((F |` {B}):{B}-->C <-> (F` B) e. C))

Proof of Theorem fressnfv

Step	Hyp	Ref	Expression
1		sneq 2417	. . . . . 6 |- (x = B -> {x} = {B})
2		reseq2 3369	. . . . . . . 8 |- ({x} = {B} -> (F |` {x}) = (F |` {B}))
3	2	feq1d 3624	. . . . . . 7 |- ({x} = {B} -> ((F |` {x}):{x}-->C <-> (F |` {B}):{x}-->C))
4		feq2 3621	. . . . . . 7 |- ({x} = {B} -> ((F |` {B}):{x}-->C <-> (F |` {B}):{B}-->C))
5	3, 4	bitrd 528	. . . . . 6 |- ({x} = {B} -> ((F |` {x}):{x}-->C <-> (F |` {B}):{B}-->C))
6	1, 5	syl 10	. . . . 5 |- (x = B -> ((F |` {x}):{x}-->C <-> (F |` {B}):{B}-->C))
7		fveq2 3724	. . . . . 6 |- (x = B -> (F` x) = (F` B))
8	7	eleq1d 1540	. . . . 5 |- (x = B -> ((F` x) e. C <-> (F` B) e. C))
9	6, 8	bibi12d 629	. . . 4 |- (x = B -> (((F |` {x}):{x}-->C <-> (F` x) e. C) <-> ((F |` {B}):{B}-->C <-> (F` B) e. C)))
10	9	imbi2d 612	. . 3 |- (x = B -> ((F Fn A -> ((F |` {x}):{x}-->C <-> (F` x) e. C)) <-> (F Fn A -> ((F |` {B}):{B}-->C <-> (F` B) e. C))))
11		fnressn 3837	. . . . 5 |- ((F Fn A /\ x e. A) -> (F |` {x}) = {<.x, (F` x)>.})
12		visset 1813	. . . . . . . . . . 11 |- x e. V
13	12	snid 2435	. . . . . . . . . 10 |- x e. {x}
14		fvres 3734	. . . . . . . . . 10 |- (x e. {x} -> ((F |` {x})` x) = (F` x))
15	13, 14	ax-mp 7	. . . . . . . . 9 |- ((F |` {x})` x) = (F` x)
16	15	opeq2i 2491	. . . . . . . 8 |- <.x, ((F |` {x})` x)>. = <.x, (F` x)>.
17	16	sneqi 2418	. . . . . . 7 |- {<.x, ((F |` {x})` x)>.} = {<.x, (F` x)>.}
18	17	eqeq2i 1485	. . . . . 6 |- ((F |` {x}) = {<.x, ((F |` {x})` x)>.} <-> (F |` {x}) = {<.x, (F` x)>.})
19		iba 642	. . . . . . . 8 |- ((F |` {x}) = {<.x, ((F |` {x})` x)>.} -> (((F |` {x})` x) e. C <-> (((F |` {x})` x) e. C /\ (F |` {x}) = {<.x, ((F |` {x})` x)>.})))
20	15	eleq1i 1537	. . . . . . . 8 |- (((F |` {x})` x) e. C <-> (F` x) e. C)
21	19, 20	syl5rbbr 535	. . . . . . 7 |- ((F |` {x}) = {<.x, ((F |` {x})` x)>.} -> ((((F |` {x})` x) e. C /\ (F |` {x}) = {<.x, ((F |` {x})` x)>.}) <-> (F` x) e. C))
22	12	fsn2 3836	. . . . . . 7 |- ((F |` {x}):{x}-->C <-> (((F |` {x})` x) e. C /\ (F |` {x}) = {<.x, ((F |` {x})` x)>.}))
23	21, 22	syl5bb 532	. . . . . 6 |- ((F |` {x}) = {<.x, ((F |` {x})` x)>.} -> ((F |` {x}):{x}-->C <-> (F` x) e. C))
24	18, 23	sylbir 201	. . . . 5 |- ((F |` {x}) = {<.x, (F` x)>.} -> ((F |` {x}):{x}-->C <-> (F` x) e. C))
25	11, 24	syl 10	. . . 4 |- ((F Fn A /\ x e. A) -> ((F |` {x}):{x}-->C <-> (F` x) e. C))
26	25	expcom 374	. . 3 |- (x e. A -> (F Fn A -> ((F |` {x}):{x}-->C <-> (F` x) e. C)))
27	10, 26	vtoclga 1852	. 2 |- (B e. A -> (F Fn A -> ((F |` {B}):{B}-->C <-> (F` B) e. C)))
28	27	impcom 351	1 |- ((F Fn A /\ B e. A) -> ((F |` {B}):{B}-->C <-> (F` B) e. C))

Syntax hints:   -> wi 3   <-> wb 146   /\ wa 223   = wceq 956   e. wcel 958  {csn 2409  <.cop 2411   |` cres 3172   Fn wfn 3177  -->wf 3178  ` cfv 3182

This theorem was proved from axioms:  ax-1 4  ax-2 5  ax-3 6  ax-mp 7  ax-7 962  ax-gen 963  ax-8 964  ax-10 966  ax-11 967  ax-12 968  ax-13 969  ax-14 970  ax-17 971  ax-4 973  ax-5o 975  ax-6o 978  ax-9o 1123  ax-10o 1140  ax-16 1210  ax-11o 1218  ax-ext 1459  ax-sep 2703  ax-nul 2710  ax-pow 2742  ax-pr 2779  ax-un 2866

This theorem depends on definitions:  df-bi 147  df-or 224  df-an 225  df-3an 777  df-ex 981  df-sb 1172  df-eu 1382  df-mo 1383  df-clab 1464  df-cleq 1469  df-clel 1472  df-ne 1587  df-rex 1650  df-reu 1651  df-v 1812  df-dif 2049  df-un 2050  df-in 2051  df-ss 2053  df-nul 2281  df-pw 2402  df-sn 2412  df-pr 2413  df-op 2416  df-uni 2504  df-br 2620  df-opab 2667  df-id 2835  df-xp 3184  df-rel 3185  df-cnv 3186  df-co 3187  df-dm 3188  df-rn 3189  df-res 3190  df-ima 3191  df-fun 3192  df-fn 3193  df-f 3194  df-f1 3195  df-fo 3196  df-f1o 3197  df-fv 3198

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