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Theorem dff13 6991
 Description: A one-to-one function in terms of function values. Compare Theorem 4.8(iv) of [Monk1] p. 43. (Contributed by NM, 29-Oct-1996.)
Assertion
Ref Expression
dff13 (𝐹:𝐴1-1𝐵 ↔ (𝐹:𝐴𝐵 ∧ ∀𝑥𝐴𝑦𝐴 ((𝐹𝑥) = (𝐹𝑦) → 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.
StepHypRef Expression
1 dff12 6548 . 2 (𝐹:𝐴1-1𝐵 ↔ (𝐹:𝐴𝐵 ∧ ∀𝑧∃*𝑥 𝑥𝐹𝑧))
2 ffn 6487 . . . 4 (𝐹:𝐴𝐵𝐹 Fn 𝐴)
3 vex 3444 . . . . . . . . . . . . . . 15 𝑥 ∈ V
4 vex 3444 . . . . . . . . . . . . . . 15 𝑧 ∈ V
53, 4breldm 5741 . . . . . . . . . . . . . 14 (𝑥𝐹𝑧𝑥 ∈ dom 𝐹)
6 fndm 6425 . . . . . . . . . . . . . . 15 (𝐹 Fn 𝐴 → dom 𝐹 = 𝐴)
76eleq2d 2875 . . . . . . . . . . . . . 14 (𝐹 Fn 𝐴 → (𝑥 ∈ dom 𝐹𝑥𝐴))
85, 7syl5ib 247 . . . . . . . . . . . . 13 (𝐹 Fn 𝐴 → (𝑥𝐹𝑧𝑥𝐴))
9 vex 3444 . . . . . . . . . . . . . . 15 𝑦 ∈ V
109, 4breldm 5741 . . . . . . . . . . . . . 14 (𝑦𝐹𝑧𝑦 ∈ dom 𝐹)
116eleq2d 2875 . . . . . . . . . . . . . 14 (𝐹 Fn 𝐴 → (𝑦 ∈ dom 𝐹𝑦𝐴))
1210, 11syl5ib 247 . . . . . . . . . . . . 13 (𝐹 Fn 𝐴 → (𝑦𝐹𝑧𝑦𝐴))
138, 12anim12d 611 . . . . . . . . . . . 12 (𝐹 Fn 𝐴 → ((𝑥𝐹𝑧𝑦𝐹𝑧) → (𝑥𝐴𝑦𝐴)))
1413pm4.71rd 566 . . . . . . . . . . 11 (𝐹 Fn 𝐴 → ((𝑥𝐹𝑧𝑦𝐹𝑧) ↔ ((𝑥𝐴𝑦𝐴) ∧ (𝑥𝐹𝑧𝑦𝐹𝑧))))
15 eqcom 2805 . . . . . . . . . . . . . . 15 (𝑧 = (𝐹𝑥) ↔ (𝐹𝑥) = 𝑧)
16 fnbrfvb 6693 . . . . . . . . . . . . . . 15 ((𝐹 Fn 𝐴𝑥𝐴) → ((𝐹𝑥) = 𝑧𝑥𝐹𝑧))
1715, 16syl5bb 286 . . . . . . . . . . . . . 14 ((𝐹 Fn 𝐴𝑥𝐴) → (𝑧 = (𝐹𝑥) ↔ 𝑥𝐹𝑧))
18 eqcom 2805 . . . . . . . . . . . . . . 15 (𝑧 = (𝐹𝑦) ↔ (𝐹𝑦) = 𝑧)
19 fnbrfvb 6693 . . . . . . . . . . . . . . 15 ((𝐹 Fn 𝐴𝑦𝐴) → ((𝐹𝑦) = 𝑧𝑦𝐹𝑧))
2018, 19syl5bb 286 . . . . . . . . . . . . . 14 ((𝐹 Fn 𝐴𝑦𝐴) → (𝑧 = (𝐹𝑦) ↔ 𝑦𝐹𝑧))
2117, 20bi2anan9 638 . . . . . . . . . . . . 13 (((𝐹 Fn 𝐴𝑥𝐴) ∧ (𝐹 Fn 𝐴𝑦𝐴)) → ((𝑧 = (𝐹𝑥) ∧ 𝑧 = (𝐹𝑦)) ↔ (𝑥𝐹𝑧𝑦𝐹𝑧)))
2221anandis 677 . . . . . . . . . . . 12 ((𝐹 Fn 𝐴 ∧ (𝑥𝐴𝑦𝐴)) → ((𝑧 = (𝐹𝑥) ∧ 𝑧 = (𝐹𝑦)) ↔ (𝑥𝐹𝑧𝑦𝐹𝑧)))
2322pm5.32da 582 . . . . . . . . . . 11 (𝐹 Fn 𝐴 → (((𝑥𝐴𝑦𝐴) ∧ (𝑧 = (𝐹𝑥) ∧ 𝑧 = (𝐹𝑦))) ↔ ((𝑥𝐴𝑦𝐴) ∧ (𝑥𝐹𝑧𝑦𝐹𝑧))))
2414, 23bitr4d 285 . . . . . . . . . 10 (𝐹 Fn 𝐴 → ((𝑥𝐹𝑧𝑦𝐹𝑧) ↔ ((𝑥𝐴𝑦𝐴) ∧ (𝑧 = (𝐹𝑥) ∧ 𝑧 = (𝐹𝑦)))))
2524imbi1d 345 . . . . . . . . 9 (𝐹 Fn 𝐴 → (((𝑥𝐹𝑧𝑦𝐹𝑧) → 𝑥 = 𝑦) ↔ (((𝑥𝐴𝑦𝐴) ∧ (𝑧 = (𝐹𝑥) ∧ 𝑧 = (𝐹𝑦))) → 𝑥 = 𝑦)))
26 impexp 454 . . . . . . . . 9 ((((𝑥𝐴𝑦𝐴) ∧ (𝑧 = (𝐹𝑥) ∧ 𝑧 = (𝐹𝑦))) → 𝑥 = 𝑦) ↔ ((𝑥𝐴𝑦𝐴) → ((𝑧 = (𝐹𝑥) ∧ 𝑧 = (𝐹𝑦)) → 𝑥 = 𝑦)))
2725, 26syl6bb 290 . . . . . . . 8 (𝐹 Fn 𝐴 → (((𝑥𝐹𝑧𝑦𝐹𝑧) → 𝑥 = 𝑦) ↔ ((𝑥𝐴𝑦𝐴) → ((𝑧 = (𝐹𝑥) ∧ 𝑧 = (𝐹𝑦)) → 𝑥 = 𝑦))))
2827albidv 1921 . . . . . . 7 (𝐹 Fn 𝐴 → (∀𝑧((𝑥𝐹𝑧𝑦𝐹𝑧) → 𝑥 = 𝑦) ↔ ∀𝑧((𝑥𝐴𝑦𝐴) → ((𝑧 = (𝐹𝑥) ∧ 𝑧 = (𝐹𝑦)) → 𝑥 = 𝑦))))
29 19.21v 1940 . . . . . . . 8 (∀𝑧((𝑥𝐴𝑦𝐴) → ((𝑧 = (𝐹𝑥) ∧ 𝑧 = (𝐹𝑦)) → 𝑥 = 𝑦)) ↔ ((𝑥𝐴𝑦𝐴) → ∀𝑧((𝑧 = (𝐹𝑥) ∧ 𝑧 = (𝐹𝑦)) → 𝑥 = 𝑦)))
30 19.23v 1943 . . . . . . . . . 10 (∀𝑧((𝑧 = (𝐹𝑥) ∧ 𝑧 = (𝐹𝑦)) → 𝑥 = 𝑦) ↔ (∃𝑧(𝑧 = (𝐹𝑥) ∧ 𝑧 = (𝐹𝑦)) → 𝑥 = 𝑦))
31 fvex 6658 . . . . . . . . . . . 12 (𝐹𝑥) ∈ V
3231eqvinc 3590 . . . . . . . . . . 11 ((𝐹𝑥) = (𝐹𝑦) ↔ ∃𝑧(𝑧 = (𝐹𝑥) ∧ 𝑧 = (𝐹𝑦)))
3332imbi1i 353 . . . . . . . . . 10 (((𝐹𝑥) = (𝐹𝑦) → 𝑥 = 𝑦) ↔ (∃𝑧(𝑧 = (𝐹𝑥) ∧ 𝑧 = (𝐹𝑦)) → 𝑥 = 𝑦))
3430, 33bitr4i 281 . . . . . . . . 9 (∀𝑧((𝑧 = (𝐹𝑥) ∧ 𝑧 = (𝐹𝑦)) → 𝑥 = 𝑦) ↔ ((𝐹𝑥) = (𝐹𝑦) → 𝑥 = 𝑦))
3534imbi2i 339 . . . . . . . 8 (((𝑥𝐴𝑦𝐴) → ∀𝑧((𝑧 = (𝐹𝑥) ∧ 𝑧 = (𝐹𝑦)) → 𝑥 = 𝑦)) ↔ ((𝑥𝐴𝑦𝐴) → ((𝐹𝑥) = (𝐹𝑦) → 𝑥 = 𝑦)))
3629, 35bitri 278 . . . . . . 7 (∀𝑧((𝑥𝐴𝑦𝐴) → ((𝑧 = (𝐹𝑥) ∧ 𝑧 = (𝐹𝑦)) → 𝑥 = 𝑦)) ↔ ((𝑥𝐴𝑦𝐴) → ((𝐹𝑥) = (𝐹𝑦) → 𝑥 = 𝑦)))
3728, 36syl6bb 290 . . . . . 6 (𝐹 Fn 𝐴 → (∀𝑧((𝑥𝐹𝑧𝑦𝐹𝑧) → 𝑥 = 𝑦) ↔ ((𝑥𝐴𝑦𝐴) → ((𝐹𝑥) = (𝐹𝑦) → 𝑥 = 𝑦))))
38372albidv 1924 . . . . 5 (𝐹 Fn 𝐴 → (∀𝑥𝑦𝑧((𝑥𝐹𝑧𝑦𝐹𝑧) → 𝑥 = 𝑦) ↔ ∀𝑥𝑦((𝑥𝐴𝑦𝐴) → ((𝐹𝑥) = (𝐹𝑦) → 𝑥 = 𝑦))))
39 breq1 5033 . . . . . . . 8 (𝑥 = 𝑦 → (𝑥𝐹𝑧𝑦𝐹𝑧))
4039mo4 2625 . . . . . . 7 (∃*𝑥 𝑥𝐹𝑧 ↔ ∀𝑥𝑦((𝑥𝐹𝑧𝑦𝐹𝑧) → 𝑥 = 𝑦))
4140albii 1821 . . . . . 6 (∀𝑧∃*𝑥 𝑥𝐹𝑧 ↔ ∀𝑧𝑥𝑦((𝑥𝐹𝑧𝑦𝐹𝑧) → 𝑥 = 𝑦))
42 alrot3 2161 . . . . . 6 (∀𝑧𝑥𝑦((𝑥𝐹𝑧𝑦𝐹𝑧) → 𝑥 = 𝑦) ↔ ∀𝑥𝑦𝑧((𝑥𝐹𝑧𝑦𝐹𝑧) → 𝑥 = 𝑦))
4341, 42bitri 278 . . . . 5 (∀𝑧∃*𝑥 𝑥𝐹𝑧 ↔ ∀𝑥𝑦𝑧((𝑥𝐹𝑧𝑦𝐹𝑧) → 𝑥 = 𝑦))
44 r2al 3166 . . . . 5 (∀𝑥𝐴𝑦𝐴 ((𝐹𝑥) = (𝐹𝑦) → 𝑥 = 𝑦) ↔ ∀𝑥𝑦((𝑥𝐴𝑦𝐴) → ((𝐹𝑥) = (𝐹𝑦) → 𝑥 = 𝑦)))
4538, 43, 443bitr4g 317 . . . 4 (𝐹 Fn 𝐴 → (∀𝑧∃*𝑥 𝑥𝐹𝑧 ↔ ∀𝑥𝐴𝑦𝐴 ((𝐹𝑥) = (𝐹𝑦) → 𝑥 = 𝑦)))
462, 45syl 17 . . 3 (𝐹:𝐴𝐵 → (∀𝑧∃*𝑥 𝑥𝐹𝑧 ↔ ∀𝑥𝐴𝑦𝐴 ((𝐹𝑥) = (𝐹𝑦) → 𝑥 = 𝑦)))
4746pm5.32i 578 . 2 ((𝐹:𝐴𝐵 ∧ ∀𝑧∃*𝑥 𝑥𝐹𝑧) ↔ (𝐹:𝐴𝐵 ∧ ∀𝑥𝐴𝑦𝐴 ((𝐹𝑥) = (𝐹𝑦) → 𝑥 = 𝑦)))
481, 47bitri 278 1 (𝐹:𝐴1-1𝐵 ↔ (𝐹:𝐴𝐵 ∧ ∀𝑥𝐴𝑦𝐴 ((𝐹𝑥) = (𝐹𝑦) → 𝑥 = 𝑦)))
 Colors of variables: wff setvar class Syntax hints:   → wi 4   ↔ wb 209   ∧ wa 399  ∀wal 1536   = wceq 1538  ∃wex 1781   ∈ wcel 2111  ∃*wmo 2596  ∀wral 3106   class class class wbr 5030  dom cdm 5519   Fn wfn 6319  ⟶wf 6320  –1-1→wf1 6321  ‘cfv 6324 This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1797  ax-4 1811  ax-5 1911  ax-6 1970  ax-7 2015  ax-8 2113  ax-9 2121  ax-10 2142  ax-11 2158  ax-12 2175  ax-ext 2770  ax-sep 5167  ax-nul 5174  ax-pr 5295 This theorem depends on definitions:  df-bi 210  df-an 400  df-or 845  df-3an 1086  df-tru 1541  df-ex 1782  df-nf 1786  df-sb 2070  df-mo 2598  df-eu 2629  df-clab 2777  df-cleq 2791  df-clel 2870  df-nfc 2938  df-ral 3111  df-rex 3112  df-v 3443  df-sbc 3721  df-dif 3884  df-un 3886  df-in 3888  df-ss 3898  df-nul 4244  df-if 4426  df-sn 4526  df-pr 4528  df-op 4532  df-uni 4801  df-br 5031  df-opab 5093  df-id 5425  df-xp 5525  df-rel 5526  df-cnv 5527  df-co 5528  df-dm 5529  df-iota 6283  df-fun 6326  df-fn 6327  df-f 6328  df-f1 6329  df-fv 6332 This theorem is referenced by:  dff13f  6992  f1veqaeq  6993  fpropnf1  7003  dff14a  7006  dff1o6  7010  fcof1  7021  nf1const  7038  soisoi  7060  f1opr  7189  f1o2ndf1  7803  fnwelem  7810  smo11  7986  tz7.48lem  8062  omsmo  8266  unxpdomlem3  8710  unfilem2  8769  fofinf1o  8785  inf3lem6  9082  r111  9190  fseqenlem1  9437  fodomacn  9469  alephf1  9498  alephiso  9511  ackbij1lem17  9649  infpssrlem5  9720  fin23lem28  9753  fin1a2lem2  9814  fin1a2lem4  9816  axcc2lem  9849  domtriomlem  9855  cnref1o  12374  injresinj  13155  om2uzf1oi  13318  cshf1  14165  wwlktovf1  14314  reeff1  15467  bitsf1  15787  crth  16107  eulerthlem2  16111  1arith  16255  vdwlem12  16320  xpsff1o  16834  setcmon  17341  fthestrcsetc  17394  embedsetcestrclem  17401  fthsetcestrc  17409  yoniso  17529  ghmf1  18382  orbsta  18438  symgextf1  18544  symgfixf1  18560  odf1  18684  kerf1ghm  19494  znf1o  20247  cygznlem3  20265  uvcf1  20485  lindff1  20513  mvrf1  20667  ply1sclf1  20925  scmatf1  21143  mdetunilem8  21231  mat2pmatf1  21341  pm2mpf1  21411  ist0-4  22341  ovolicc2lem4  24131  recosf1o  25134  efif1olem4  25144  basellem4  25676  dvdsmulf1o  25786  lgsqrlem2  25938  lgseisenlem2  25967  2lgslem1b  25983  axlowdimlem15  26757  upgrwlkdvdelem  27532  wlkswwlksf1o  27672  wwlksnextinj  27692  clwlkclwwlkf1  27802  clwwlkf1  27841  frgrncvvdeqlem8  28098  numclwwlk1lem2f1  28149  pjmf1  29506  unopf1o  29706  2ndresdju  30418  fnpreimac  30441  s3f1  30656  ccatf1  30658  swrdf1  30663  tocyccntz  30843  dff15  32475  f1resrcmplf1d  32482  f1resfz0f1d  32483  erdszelem9  32571  mrsubff1  32886  msubff1  32928  mvhf1  32931  f1omptsnlem  34769  fvineqsnf1  34843  fvineqsneu  34844  poimirlem26  35099  poimirlem27  35100  grpokerinj  35347  cdleme50f1  37855  dihf11  38579  dnnumch3  40006  wessf1ornlem  41826  projf1o  41840  sumnnodd  42287  dvnprodlem1  42603  fourierdlem34  42798  fourierdlem51  42814  imasetpreimafvbijlemf1  43936  fargshiftf1  43973  sprsymrelf1  44028  prproropf1o  44039  fmtnof1  44067  prmdvdsfmtnof1  44119  isomuspgrlem2c  44363  uspgrsprf1  44390  1arymaptf1  45070  2arymaptf1  45081  rrx2xpref1o  45146
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