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Theorem dff13 5676
 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 5334 . 2 (𝐹:𝐴1-1𝐵 ↔ (𝐹:𝐴𝐵 ∧ ∀𝑧∃*𝑥 𝑥𝐹𝑧))
2 ffn 5279 . . . 4 (𝐹:𝐴𝐵𝐹 Fn 𝐴)
3 vex 2692 . . . . . . . . . . . . . . 15 𝑥 ∈ V
4 vex 2692 . . . . . . . . . . . . . . 15 𝑧 ∈ V
53, 4breldm 4750 . . . . . . . . . . . . . 14 (𝑥𝐹𝑧𝑥 ∈ dom 𝐹)
6 fndm 5229 . . . . . . . . . . . . . . 15 (𝐹 Fn 𝐴 → dom 𝐹 = 𝐴)
76eleq2d 2210 . . . . . . . . . . . . . 14 (𝐹 Fn 𝐴 → (𝑥 ∈ dom 𝐹𝑥𝐴))
85, 7syl5ib 153 . . . . . . . . . . . . 13 (𝐹 Fn 𝐴 → (𝑥𝐹𝑧𝑥𝐴))
9 vex 2692 . . . . . . . . . . . . . . 15 𝑦 ∈ V
109, 4breldm 4750 . . . . . . . . . . . . . 14 (𝑦𝐹𝑧𝑦 ∈ dom 𝐹)
116eleq2d 2210 . . . . . . . . . . . . . 14 (𝐹 Fn 𝐴 → (𝑦 ∈ dom 𝐹𝑦𝐴))
1210, 11syl5ib 153 . . . . . . . . . . . . 13 (𝐹 Fn 𝐴 → (𝑦𝐹𝑧𝑦𝐴))
138, 12anim12d 333 . . . . . . . . . . . 12 (𝐹 Fn 𝐴 → ((𝑥𝐹𝑧𝑦𝐹𝑧) → (𝑥𝐴𝑦𝐴)))
1413pm4.71rd 392 . . . . . . . . . . 11 (𝐹 Fn 𝐴 → ((𝑥𝐹𝑧𝑦𝐹𝑧) ↔ ((𝑥𝐴𝑦𝐴) ∧ (𝑥𝐹𝑧𝑦𝐹𝑧))))
15 eqcom 2142 . . . . . . . . . . . . . . 15 (𝑧 = (𝐹𝑥) ↔ (𝐹𝑥) = 𝑧)
16 fnbrfvb 5469 . . . . . . . . . . . . . . 15 ((𝐹 Fn 𝐴𝑥𝐴) → ((𝐹𝑥) = 𝑧𝑥𝐹𝑧))
1715, 16syl5bb 191 . . . . . . . . . . . . . 14 ((𝐹 Fn 𝐴𝑥𝐴) → (𝑧 = (𝐹𝑥) ↔ 𝑥𝐹𝑧))
18 eqcom 2142 . . . . . . . . . . . . . . 15 (𝑧 = (𝐹𝑦) ↔ (𝐹𝑦) = 𝑧)
19 fnbrfvb 5469 . . . . . . . . . . . . . . 15 ((𝐹 Fn 𝐴𝑦𝐴) → ((𝐹𝑦) = 𝑧𝑦𝐹𝑧))
2018, 19syl5bb 191 . . . . . . . . . . . . . 14 ((𝐹 Fn 𝐴𝑦𝐴) → (𝑧 = (𝐹𝑦) ↔ 𝑦𝐹𝑧))
2117, 20bi2anan9 596 . . . . . . . . . . . . 13 (((𝐹 Fn 𝐴𝑥𝐴) ∧ (𝐹 Fn 𝐴𝑦𝐴)) → ((𝑧 = (𝐹𝑥) ∧ 𝑧 = (𝐹𝑦)) ↔ (𝑥𝐹𝑧𝑦𝐹𝑧)))
2221anandis 582 . . . . . . . . . . . 12 ((𝐹 Fn 𝐴 ∧ (𝑥𝐴𝑦𝐴)) → ((𝑧 = (𝐹𝑥) ∧ 𝑧 = (𝐹𝑦)) ↔ (𝑥𝐹𝑧𝑦𝐹𝑧)))
2322pm5.32da 448 . . . . . . . . . . 11 (𝐹 Fn 𝐴 → (((𝑥𝐴𝑦𝐴) ∧ (𝑧 = (𝐹𝑥) ∧ 𝑧 = (𝐹𝑦))) ↔ ((𝑥𝐴𝑦𝐴) ∧ (𝑥𝐹𝑧𝑦𝐹𝑧))))
2414, 23bitr4d 190 . . . . . . . . . 10 (𝐹 Fn 𝐴 → ((𝑥𝐹𝑧𝑦𝐹𝑧) ↔ ((𝑥𝐴𝑦𝐴) ∧ (𝑧 = (𝐹𝑥) ∧ 𝑧 = (𝐹𝑦)))))
2524imbi1d 230 . . . . . . . . 9 (𝐹 Fn 𝐴 → (((𝑥𝐹𝑧𝑦𝐹𝑧) → 𝑥 = 𝑦) ↔ (((𝑥𝐴𝑦𝐴) ∧ (𝑧 = (𝐹𝑥) ∧ 𝑧 = (𝐹𝑦))) → 𝑥 = 𝑦)))
26 impexp 261 . . . . . . . . 9 ((((𝑥𝐴𝑦𝐴) ∧ (𝑧 = (𝐹𝑥) ∧ 𝑧 = (𝐹𝑦))) → 𝑥 = 𝑦) ↔ ((𝑥𝐴𝑦𝐴) → ((𝑧 = (𝐹𝑥) ∧ 𝑧 = (𝐹𝑦)) → 𝑥 = 𝑦)))
2725, 26syl6bb 195 . . . . . . . 8 (𝐹 Fn 𝐴 → (((𝑥𝐹𝑧𝑦𝐹𝑧) → 𝑥 = 𝑦) ↔ ((𝑥𝐴𝑦𝐴) → ((𝑧 = (𝐹𝑥) ∧ 𝑧 = (𝐹𝑦)) → 𝑥 = 𝑦))))
2827albidv 1797 . . . . . . 7 (𝐹 Fn 𝐴 → (∀𝑧((𝑥𝐹𝑧𝑦𝐹𝑧) → 𝑥 = 𝑦) ↔ ∀𝑧((𝑥𝐴𝑦𝐴) → ((𝑧 = (𝐹𝑥) ∧ 𝑧 = (𝐹𝑦)) → 𝑥 = 𝑦))))
29 19.21v 1846 . . . . . . . 8 (∀𝑧((𝑥𝐴𝑦𝐴) → ((𝑧 = (𝐹𝑥) ∧ 𝑧 = (𝐹𝑦)) → 𝑥 = 𝑦)) ↔ ((𝑥𝐴𝑦𝐴) → ∀𝑧((𝑧 = (𝐹𝑥) ∧ 𝑧 = (𝐹𝑦)) → 𝑥 = 𝑦)))
30 funfvex 5445 . . . . . . . . . . . . . 14 ((Fun 𝐹𝑥 ∈ dom 𝐹) → (𝐹𝑥) ∈ V)
3130funfni 5230 . . . . . . . . . . . . 13 ((𝐹 Fn 𝐴𝑥𝐴) → (𝐹𝑥) ∈ V)
32 eqvincg 2812 . . . . . . . . . . . . 13 ((𝐹𝑥) ∈ V → ((𝐹𝑥) = (𝐹𝑦) ↔ ∃𝑧(𝑧 = (𝐹𝑥) ∧ 𝑧 = (𝐹𝑦))))
3331, 32syl 14 . . . . . . . . . . . 12 ((𝐹 Fn 𝐴𝑥𝐴) → ((𝐹𝑥) = (𝐹𝑦) ↔ ∃𝑧(𝑧 = (𝐹𝑥) ∧ 𝑧 = (𝐹𝑦))))
3433imbi1d 230 . . . . . . . . . . 11 ((𝐹 Fn 𝐴𝑥𝐴) → (((𝐹𝑥) = (𝐹𝑦) → 𝑥 = 𝑦) ↔ (∃𝑧(𝑧 = (𝐹𝑥) ∧ 𝑧 = (𝐹𝑦)) → 𝑥 = 𝑦)))
35 19.23v 1856 . . . . . . . . . . 11 (∀𝑧((𝑧 = (𝐹𝑥) ∧ 𝑧 = (𝐹𝑦)) → 𝑥 = 𝑦) ↔ (∃𝑧(𝑧 = (𝐹𝑥) ∧ 𝑧 = (𝐹𝑦)) → 𝑥 = 𝑦))
3634, 35syl6rbbr 198 . . . . . . . . . 10 ((𝐹 Fn 𝐴𝑥𝐴) → (∀𝑧((𝑧 = (𝐹𝑥) ∧ 𝑧 = (𝐹𝑦)) → 𝑥 = 𝑦) ↔ ((𝐹𝑥) = (𝐹𝑦) → 𝑥 = 𝑦)))
3736adantrr 471 . . . . . . . . 9 ((𝐹 Fn 𝐴 ∧ (𝑥𝐴𝑦𝐴)) → (∀𝑧((𝑧 = (𝐹𝑥) ∧ 𝑧 = (𝐹𝑦)) → 𝑥 = 𝑦) ↔ ((𝐹𝑥) = (𝐹𝑦) → 𝑥 = 𝑦)))
3837pm5.74da 440 . . . . . . . 8 (𝐹 Fn 𝐴 → (((𝑥𝐴𝑦𝐴) → ∀𝑧((𝑧 = (𝐹𝑥) ∧ 𝑧 = (𝐹𝑦)) → 𝑥 = 𝑦)) ↔ ((𝑥𝐴𝑦𝐴) → ((𝐹𝑥) = (𝐹𝑦) → 𝑥 = 𝑦))))
3929, 38syl5bb 191 . . . . . . 7 (𝐹 Fn 𝐴 → (∀𝑧((𝑥𝐴𝑦𝐴) → ((𝑧 = (𝐹𝑥) ∧ 𝑧 = (𝐹𝑦)) → 𝑥 = 𝑦)) ↔ ((𝑥𝐴𝑦𝐴) → ((𝐹𝑥) = (𝐹𝑦) → 𝑥 = 𝑦))))
4028, 39bitrd 187 . . . . . 6 (𝐹 Fn 𝐴 → (∀𝑧((𝑥𝐹𝑧𝑦𝐹𝑧) → 𝑥 = 𝑦) ↔ ((𝑥𝐴𝑦𝐴) → ((𝐹𝑥) = (𝐹𝑦) → 𝑥 = 𝑦))))
41402albidv 1840 . . . . 5 (𝐹 Fn 𝐴 → (∀𝑥𝑦𝑧((𝑥𝐹𝑧𝑦𝐹𝑧) → 𝑥 = 𝑦) ↔ ∀𝑥𝑦((𝑥𝐴𝑦𝐴) → ((𝐹𝑥) = (𝐹𝑦) → 𝑥 = 𝑦))))
42 breq1 3939 . . . . . . . 8 (𝑥 = 𝑦 → (𝑥𝐹𝑧𝑦𝐹𝑧))
4342mo4 2061 . . . . . . 7 (∃*𝑥 𝑥𝐹𝑧 ↔ ∀𝑥𝑦((𝑥𝐹𝑧𝑦𝐹𝑧) → 𝑥 = 𝑦))
4443albii 1447 . . . . . 6 (∀𝑧∃*𝑥 𝑥𝐹𝑧 ↔ ∀𝑧𝑥𝑦((𝑥𝐹𝑧𝑦𝐹𝑧) → 𝑥 = 𝑦))
45 alrot3 1462 . . . . . 6 (∀𝑧𝑥𝑦((𝑥𝐹𝑧𝑦𝐹𝑧) → 𝑥 = 𝑦) ↔ ∀𝑥𝑦𝑧((𝑥𝐹𝑧𝑦𝐹𝑧) → 𝑥 = 𝑦))
4644, 45bitri 183 . . . . 5 (∀𝑧∃*𝑥 𝑥𝐹𝑧 ↔ ∀𝑥𝑦𝑧((𝑥𝐹𝑧𝑦𝐹𝑧) → 𝑥 = 𝑦))
47 r2al 2457 . . . . 5 (∀𝑥𝐴𝑦𝐴 ((𝐹𝑥) = (𝐹𝑦) → 𝑥 = 𝑦) ↔ ∀𝑥𝑦((𝑥𝐴𝑦𝐴) → ((𝐹𝑥) = (𝐹𝑦) → 𝑥 = 𝑦)))
4841, 46, 473bitr4g 222 . . . 4 (𝐹 Fn 𝐴 → (∀𝑧∃*𝑥 𝑥𝐹𝑧 ↔ ∀𝑥𝐴𝑦𝐴 ((𝐹𝑥) = (𝐹𝑦) → 𝑥 = 𝑦)))
492, 48syl 14 . . 3 (𝐹:𝐴𝐵 → (∀𝑧∃*𝑥 𝑥𝐹𝑧 ↔ ∀𝑥𝐴𝑦𝐴 ((𝐹𝑥) = (𝐹𝑦) → 𝑥 = 𝑦)))
5049pm5.32i 450 . 2 ((𝐹:𝐴𝐵 ∧ ∀𝑧∃*𝑥 𝑥𝐹𝑧) ↔ (𝐹:𝐴𝐵 ∧ ∀𝑥𝐴𝑦𝐴 ((𝐹𝑥) = (𝐹𝑦) → 𝑥 = 𝑦)))
511, 50bitri 183 1 (𝐹:𝐴1-1𝐵 ↔ (𝐹:𝐴𝐵 ∧ ∀𝑥𝐴𝑦𝐴 ((𝐹𝑥) = (𝐹𝑦) → 𝑥 = 𝑦)))
 Colors of variables: wff set class Syntax hints:   → wi 4   ∧ wa 103   ↔ wb 104  ∀wal 1330   = wceq 1332  ∃wex 1469   ∈ wcel 1481  ∃*wmo 2001  ∀wral 2417  Vcvv 2689   class class class wbr 3936  dom cdm 4546   Fn wfn 5125  ⟶wf 5126  –1-1→wf1 5127  ‘cfv 5130 This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-io 699  ax-5 1424  ax-7 1425  ax-gen 1426  ax-ie1 1470  ax-ie2 1471  ax-8 1483  ax-10 1484  ax-11 1485  ax-i12 1486  ax-bndl 1487  ax-4 1488  ax-14 1493  ax-17 1507  ax-i9 1511  ax-ial 1515  ax-i5r 1516  ax-ext 2122  ax-sep 4053  ax-pow 4105  ax-pr 4138 This theorem depends on definitions:  df-bi 116  df-3an 965  df-tru 1335  df-nf 1438  df-sb 1737  df-eu 2003  df-mo 2004  df-clab 2127  df-cleq 2133  df-clel 2136  df-nfc 2271  df-ral 2422  df-rex 2423  df-v 2691  df-sbc 2913  df-un 3079  df-in 3081  df-ss 3088  df-pw 3516  df-sn 3537  df-pr 3538  df-op 3540  df-uni 3744  df-br 3937  df-opab 3997  df-id 4222  df-xp 4552  df-rel 4553  df-cnv 4554  df-co 4555  df-dm 4556  df-iota 5095  df-fun 5132  df-fn 5133  df-f 5134  df-f1 5135  df-fv 5138 This theorem is referenced by:  f1veqaeq  5677  dff13f  5678  dff1o6  5684  fcof1  5691  f1o2ndf1  6132  cc2lem  7097  cnref1o  9468  frec2uzf1od  10209  iseqf1olemqf1o  10296  reeff1  11441  crth  11934  ioocosf1o  12981  peano4nninf  13373  exmidsbthrlem  13390
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