Theorem dff13 5471

Description: A one-to-one function in terms of function values. Compare Theorem 4.8(iv) of [Monk1] p. 43. (Contributed by set.mm contributors, 29-Oct-1996.)

Assertion

Ref	Expression
dff13	|- (F:A-1-1->B <-> (F:A-->B /\ A.x e. A A.y e. A ((F` x) = (F` y) -> x = y)))

Distinct variable groups:   x,y,A   x,F,y

Allowed substitution hints:   B(x,y)

Proof of Theorem dff13

Dummy variable z is distinct from all other variables.

Step	Hyp	Ref	Expression
1		dff12 5257	. 2 |- (F:A-1-1->B <-> (F:A-->B /\ A.zE*x xFz))
2		ffn 5223	. . . 4 |- (F:A-->B -> F Fn A)
3		breldm 4911	. . . . . . . . . . . . . 14 |- (xFz -> x e. dom F)
4		fndm 5182	. . . . . . . . . . . . . . 15 |- (F Fn A -> dom F = A)
5	4	eleq2d 2420	. . . . . . . . . . . . . 14 |- (F Fn A -> (x e. dom F <-> x e. A))
6	3, 5	syl5ib 210	. . . . . . . . . . . . 13 |- (F Fn A -> (xFz -> x e. A))
7		breldm 4911	. . . . . . . . . . . . . 14 |- (yFz -> y e. dom F)
8	4	eleq2d 2420	. . . . . . . . . . . . . 14 |- (F Fn A -> (y e. dom F <-> y e. A))
9	7, 8	syl5ib 210	. . . . . . . . . . . . 13 |- (F Fn A -> (yFz -> y e. A))
10	6, 9	anim12d 546	. . . . . . . . . . . 12 |- (F Fn A -> ((xFz /\ yFz) -> (x e. A /\ y e. A)))
11	10	pm4.71rd 616	. . . . . . . . . . 11 |- (F Fn A -> ((xFz /\ yFz) <-> ((x e. A /\ y e. A) /\ (xFz /\ yFz))))
12		eqcom 2355	. . . . . . . . . . . . . . 15 |- (z = (F` x) <-> (F` x) = z)
13		fnbrfvb 5358	. . . . . . . . . . . . . . 15 |- ((F Fn A /\ x e. A) -> ((F` x) = z <-> xFz))
14	12, 13	syl5bb 248	. . . . . . . . . . . . . 14 |- ((F Fn A /\ x e. A) -> (z = (F` x) <-> xFz))
15		eqcom 2355	. . . . . . . . . . . . . . 15 |- (z = (F` y) <-> (F` y) = z)
16		fnbrfvb 5358	. . . . . . . . . . . . . . 15 |- ((F Fn A /\ y e. A) -> ((F` y) = z <-> yFz))
17	15, 16	syl5bb 248	. . . . . . . . . . . . . 14 |- ((F Fn A /\ y e. A) -> (z = (F` y) <-> yFz))
18	14, 17	bi2anan9 843	. . . . . . . . . . . . 13 |- (((F Fn A /\ x e. A) /\ (F Fn A /\ y e. A)) -> ((z = (F` x) /\ z = (F` y)) <-> (xFz /\ yFz)))
19	18	anandis 803	. . . . . . . . . . . 12 |- ((F Fn A /\ (x e. A /\ y e. A)) -> ((z = (F` x) /\ z = (F` y)) <-> (xFz /\ yFz)))
20	19	pm5.32da 622	. . . . . . . . . . 11 |- (F Fn A -> (((x e. A /\ y e. A) /\ (z = (F` x) /\ z = (F` y))) <-> ((x e. A /\ y e. A) /\ (xFz /\ yFz))))
21	11, 20	bitr4d 247	. . . . . . . . . 10 |- (F Fn A -> ((xFz /\ yFz) <-> ((x e. A /\ y e. A) /\ (z = (F` x) /\ z = (F` y)))))
22	21	imbi1d 308	. . . . . . . . 9 |- (F Fn A -> (((xFz /\ yFz) -> x = y) <-> (((x e. A /\ y e. A) /\ (z = (F` x) /\ z = (F` y))) -> x = y)))
23		impexp 433	. . . . . . . . 9 |- ((((x e. A /\ y e. A) /\ (z = (F` x) /\ z = (F` y))) -> x = y) <-> ((x e. A /\ y e. A) -> ((z = (F` x) /\ z = (F` y)) -> x = y)))
24	22, 23	syl6bb 252	. . . . . . . 8 |- (F Fn A -> (((xFz /\ yFz) -> x = y) <-> ((x e. A /\ y e. A) -> ((z = (F` x) /\ z = (F` y)) -> x = y))))
25	24	albidv 1625	. . . . . . 7 |- (F Fn A -> (A.z((xFz /\ yFz) -> x = y) <-> A.z((x e. A /\ y e. A) -> ((z = (F` x) /\ z = (F` y)) -> x = y))))
26		19.21v 1890	. . . . . . . 8 |- (A.z((x e. A /\ y e. A) -> ((z = (F` x) /\ z = (F` y)) -> x = y)) <-> ((x e. A /\ y e. A) -> A.z((z = (F` x) /\ z = (F` y)) -> x = y)))
27		19.23v 1891	. . . . . . . . . 10 |- (A.z((z = (F` x) /\ z = (F` y)) -> x = y) <-> (E.z(z = (F` x) /\ z = (F` y)) -> x = y))
28		fvex 5339	. . . . . . . . . . . 12 |- (F` x) e. _V
29	28	eqvinc 2966	. . . . . . . . . . 11 |- ((F` x) = (F` y) <-> E.z(z = (F` x) /\ z = (F` y)))
30	29	imbi1i 315	. . . . . . . . . 10 |- (((F` x) = (F` y) -> x = y) <-> (E.z(z = (F` x) /\ z = (F` y)) -> x = y))
31	27, 30	bitr4i 243	. . . . . . . . 9 |- (A.z((z = (F` x) /\ z = (F` y)) -> x = y) <-> ((F` x) = (F` y) -> x = y))
32	31	imbi2i 303	. . . . . . . 8 |- (((x e. A /\ y e. A) -> A.z((z = (F` x) /\ z = (F` y)) -> x = y)) <-> ((x e. A /\ y e. A) -> ((F` x) = (F` y) -> x = y)))
33	26, 32	bitri 240	. . . . . . 7 |- (A.z((x e. A /\ y e. A) -> ((z = (F` x) /\ z = (F` y)) -> x = y)) <-> ((x e. A /\ y e. A) -> ((F` x) = (F` y) -> x = y)))
34	25, 33	syl6bb 252	. . . . . 6 |- (F Fn A -> (A.z((xFz /\ yFz) -> x = y) <-> ((x e. A /\ y e. A) -> ((F` x) = (F` y) -> x = y))))
35	34	2albidv 1627	. . . . 5 |- (F Fn A -> (A.xA.yA.z((xFz /\ yFz) -> x = y) <-> A.xA.y((x e. A /\ y e. A) -> ((F` x) = (F` y) -> x = y))))
36		breq1 4642	. . . . . . . 8 |- (x = y -> (xFz <-> yFz))
37	36	mo4 2237	. . . . . . 7 |- (E*x xFz <-> A.xA.y((xFz /\ yFz) -> x = y))
38	37	albii 1566	. . . . . 6 |- (A.zE*x xFz <-> A.zA.xA.y((xFz /\ yFz) -> x = y))
39		alcom 1737	. . . . . 6 |- (A.zA.xA.y((xFz /\ yFz) -> x = y) <-> A.xA.zA.y((xFz /\ yFz) -> x = y))
40		alcom 1737	. . . . . . 7 |- (A.zA.y((xFz /\ yFz) -> x = y) <-> A.yA.z((xFz /\ yFz) -> x = y))
41	40	albii 1566	. . . . . 6 |- (A.xA.zA.y((xFz /\ yFz) -> x = y) <-> A.xA.yA.z((xFz /\ yFz) -> x = y))
42	38, 39, 41	3bitri 262	. . . . 5 |- (A.zE*x xFz <-> A.xA.yA.z((xFz /\ yFz) -> x = y))
43		r2al 2651	. . . . 5 |- (A.x e. A A.y e. A ((F` x) = (F` y) -> x = y) <-> A.xA.y((x e. A /\ y e. A) -> ((F` x) = (F` y) -> x = y)))
44	35, 42, 43	3bitr4g 279	. . . 4 |- (F Fn A -> (A.zE*x xFz <-> A.x e. A A.y e. A ((F` x) = (F` y) -> x = y)))
45	2, 44	syl 15	. . 3 |- (F:A-->B -> (A.zE*x xFz <-> A.x e. A A.y e. A ((F` x) = (F` y) -> x = y)))
46	45	pm5.32i 618	. 2 |- ((F:A-->B /\ A.zE*x xFz) <-> (F:A-->B /\ A.x e. A A.y e. A ((F` x) = (F` y) -> x = y)))
47	1, 46	bitri 240	1 |- (F:A-1-1->B <-> (F:A-->B /\ A.x e. A A.y e. A ((F` x) = (F` y) -> x = y)))

Syntax hints:   -> wi 4   <-> wb 176   /\ wa 358  A.wal 1540  E.wex 1541   = wceq 1642   e. wcel 1710  E*wmo 2205  A.wral 2614   class class class wbr 4639  dom cdm 4772   Fn wfn 4776  -->wf 4777  -1-1->wf1 4778  ` cfv 4781

This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-3 7  ax-mp 8  ax-gen 1546  ax-5 1557  ax-17 1616  ax-9 1654  ax-8 1675  ax-13 1712  ax-14 1714  ax-6 1729  ax-7 1734  ax-11 1746  ax-12 1925  ax-ext 2334  ax-nin 4078  ax-xp 4079  ax-cnv 4080  ax-1c 4081  ax-sset 4082  ax-si 4083  ax-ins2 4084  ax-ins3 4085  ax-typlower 4086  ax-sn 4087

This theorem depends on definitions:  df-bi 177  df-or 359  df-an 360  df-3or 935  df-3an 936  df-nan 1288  df-tru 1319  df-ex 1542  df-nf 1545  df-sb 1649  df-eu 2208  df-mo 2209  df-clab 2340  df-cleq 2346  df-clel 2349  df-nfc 2478  df-ne 2518  df-ral 2619  df-rex 2620  df-reu 2621  df-rmo 2622  df-rab 2623  df-v 2861  df-sbc 3047  df-nin 3211  df-compl 3212  df-in 3213  df-un 3214  df-dif 3215  df-symdif 3216  df-ss 3259  df-pss 3261  df-nul 3551  df-if 3663  df-pw 3724  df-sn 3741  df-pr 3742  df-uni 3892  df-int 3927  df-opk 4058  df-1c 4136  df-pw1 4137  df-uni1 4138  df-xpk 4185  df-cnvk 4186  df-ins2k 4187  df-ins3k 4188  df-imak 4189  df-cok 4190  df-p6 4191  df-sik 4192  df-ssetk 4193  df-imagek 4194  df-idk 4195  df-iota 4339  df-0c 4377  df-addc 4378  df-nnc 4379  df-fin 4380  df-lefin 4440  df-ltfin 4441  df-ncfin 4442  df-tfin 4443  df-evenfin 4444  df-oddfin 4445  df-sfin 4446  df-spfin 4447  df-phi 4565  df-op 4566  df-proj1 4567  df-proj2 4568  df-opab 4623  df-br 4640  df-co 4726  df-ima 4727  df-id 4767  df-cnv 4785  df-rn 4786  df-dm 4787  df-fun 4789  df-fn 4790  df-f 4791  df-f1 4792  df-fv 4795

This theorem is referenced by:  dff13f  5472  f1fveq  5473  dff1o6  5475