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Theorem dom2lem 6282
 Description: A mapping (first hypothesis) that is one-to-one (second hypothesis) implies its domain is dominated by its codomain. (Contributed by NM, 24-Jul-2004.)
Hypotheses
Ref Expression
dom2d.1 (𝜑 → (𝑥𝐴𝐶𝐵))
dom2d.2 (𝜑 → ((𝑥𝐴𝑦𝐴) → (𝐶 = 𝐷𝑥 = 𝑦)))
Assertion
Ref Expression
dom2lem (𝜑 → (𝑥𝐴𝐶):𝐴1-1𝐵)
Distinct variable groups:   𝑥,𝑦,𝐴   𝑥,𝐵,𝑦   𝑦,𝐶   𝑥,𝐷   𝜑,𝑥,𝑦
Allowed substitution hints:   𝐶(𝑥)   𝐷(𝑦)

Proof of Theorem dom2lem
StepHypRef Expression
1 dom2d.1 . . . 4 (𝜑 → (𝑥𝐴𝐶𝐵))
21ralrimiv 2408 . . 3 (𝜑 → ∀𝑥𝐴 𝐶𝐵)
3 eqid 2056 . . . 4 (𝑥𝐴𝐶) = (𝑥𝐴𝐶)
43fmpt 5346 . . 3 (∀𝑥𝐴 𝐶𝐵 ↔ (𝑥𝐴𝐶):𝐴𝐵)
52, 4sylib 131 . 2 (𝜑 → (𝑥𝐴𝐶):𝐴𝐵)
61imp 119 . . . . . . 7 ((𝜑𝑥𝐴) → 𝐶𝐵)
73fvmpt2 5281 . . . . . . . 8 ((𝑥𝐴𝐶𝐵) → ((𝑥𝐴𝐶)‘𝑥) = 𝐶)
87adantll 453 . . . . . . 7 (((𝜑𝑥𝐴) ∧ 𝐶𝐵) → ((𝑥𝐴𝐶)‘𝑥) = 𝐶)
96, 8mpdan 406 . . . . . 6 ((𝜑𝑥𝐴) → ((𝑥𝐴𝐶)‘𝑥) = 𝐶)
109adantrr 456 . . . . 5 ((𝜑 ∧ (𝑥𝐴𝑦𝐴)) → ((𝑥𝐴𝐶)‘𝑥) = 𝐶)
11 nfv 1437 . . . . . . . 8 𝑥(𝜑𝑦𝐴)
12 nffvmpt1 5213 . . . . . . . . 9 𝑥((𝑥𝐴𝐶)‘𝑦)
1312nfeq1 2203 . . . . . . . 8 𝑥((𝑥𝐴𝐶)‘𝑦) = 𝐷
1411, 13nfim 1480 . . . . . . 7 𝑥((𝜑𝑦𝐴) → ((𝑥𝐴𝐶)‘𝑦) = 𝐷)
15 eleq1 2116 . . . . . . . . . 10 (𝑥 = 𝑦 → (𝑥𝐴𝑦𝐴))
1615anbi2d 445 . . . . . . . . 9 (𝑥 = 𝑦 → ((𝜑𝑥𝐴) ↔ (𝜑𝑦𝐴)))
1716imbi1d 224 . . . . . . . 8 (𝑥 = 𝑦 → (((𝜑𝑥𝐴) → ((𝑥𝐴𝐶)‘𝑥) = 𝐶) ↔ ((𝜑𝑦𝐴) → ((𝑥𝐴𝐶)‘𝑥) = 𝐶)))
1815anbi1d 446 . . . . . . . . . . . 12 (𝑥 = 𝑦 → ((𝑥𝐴𝑦𝐴) ↔ (𝑦𝐴𝑦𝐴)))
19 anidm 382 . . . . . . . . . . . 12 ((𝑦𝐴𝑦𝐴) ↔ 𝑦𝐴)
2018, 19syl6bb 189 . . . . . . . . . . 11 (𝑥 = 𝑦 → ((𝑥𝐴𝑦𝐴) ↔ 𝑦𝐴))
2120anbi2d 445 . . . . . . . . . 10 (𝑥 = 𝑦 → ((𝜑 ∧ (𝑥𝐴𝑦𝐴)) ↔ (𝜑𝑦𝐴)))
22 fveq2 5205 . . . . . . . . . . . . 13 (𝑥 = 𝑦 → ((𝑥𝐴𝐶)‘𝑥) = ((𝑥𝐴𝐶)‘𝑦))
2322adantr 265 . . . . . . . . . . . 12 ((𝑥 = 𝑦 ∧ (𝜑 ∧ (𝑥𝐴𝑦𝐴))) → ((𝑥𝐴𝐶)‘𝑥) = ((𝑥𝐴𝐶)‘𝑦))
24 dom2d.2 . . . . . . . . . . . . . 14 (𝜑 → ((𝑥𝐴𝑦𝐴) → (𝐶 = 𝐷𝑥 = 𝑦)))
2524imp 119 . . . . . . . . . . . . 13 ((𝜑 ∧ (𝑥𝐴𝑦𝐴)) → (𝐶 = 𝐷𝑥 = 𝑦))
2625biimparc 287 . . . . . . . . . . . 12 ((𝑥 = 𝑦 ∧ (𝜑 ∧ (𝑥𝐴𝑦𝐴))) → 𝐶 = 𝐷)
2723, 26eqeq12d 2070 . . . . . . . . . . 11 ((𝑥 = 𝑦 ∧ (𝜑 ∧ (𝑥𝐴𝑦𝐴))) → (((𝑥𝐴𝐶)‘𝑥) = 𝐶 ↔ ((𝑥𝐴𝐶)‘𝑦) = 𝐷))
2827ex 112 . . . . . . . . . 10 (𝑥 = 𝑦 → ((𝜑 ∧ (𝑥𝐴𝑦𝐴)) → (((𝑥𝐴𝐶)‘𝑥) = 𝐶 ↔ ((𝑥𝐴𝐶)‘𝑦) = 𝐷)))
2921, 28sylbird 163 . . . . . . . . 9 (𝑥 = 𝑦 → ((𝜑𝑦𝐴) → (((𝑥𝐴𝐶)‘𝑥) = 𝐶 ↔ ((𝑥𝐴𝐶)‘𝑦) = 𝐷)))
3029pm5.74d 175 . . . . . . . 8 (𝑥 = 𝑦 → (((𝜑𝑦𝐴) → ((𝑥𝐴𝐶)‘𝑥) = 𝐶) ↔ ((𝜑𝑦𝐴) → ((𝑥𝐴𝐶)‘𝑦) = 𝐷)))
3117, 30bitrd 181 . . . . . . 7 (𝑥 = 𝑦 → (((𝜑𝑥𝐴) → ((𝑥𝐴𝐶)‘𝑥) = 𝐶) ↔ ((𝜑𝑦𝐴) → ((𝑥𝐴𝐶)‘𝑦) = 𝐷)))
3214, 31, 9chvar 1656 . . . . . 6 ((𝜑𝑦𝐴) → ((𝑥𝐴𝐶)‘𝑦) = 𝐷)
3332adantrl 455 . . . . 5 ((𝜑 ∧ (𝑥𝐴𝑦𝐴)) → ((𝑥𝐴𝐶)‘𝑦) = 𝐷)
3410, 33eqeq12d 2070 . . . 4 ((𝜑 ∧ (𝑥𝐴𝑦𝐴)) → (((𝑥𝐴𝐶)‘𝑥) = ((𝑥𝐴𝐶)‘𝑦) ↔ 𝐶 = 𝐷))
3525biimpd 136 . . . 4 ((𝜑 ∧ (𝑥𝐴𝑦𝐴)) → (𝐶 = 𝐷𝑥 = 𝑦))
3634, 35sylbid 143 . . 3 ((𝜑 ∧ (𝑥𝐴𝑦𝐴)) → (((𝑥𝐴𝐶)‘𝑥) = ((𝑥𝐴𝐶)‘𝑦) → 𝑥 = 𝑦))
3736ralrimivva 2418 . 2 (𝜑 → ∀𝑥𝐴𝑦𝐴 (((𝑥𝐴𝐶)‘𝑥) = ((𝑥𝐴𝐶)‘𝑦) → 𝑥 = 𝑦))
38 nfmpt1 3877 . . 3 𝑥(𝑥𝐴𝐶)
39 nfcv 2194 . . 3 𝑦(𝑥𝐴𝐶)
4038, 39dff13f 5436 . 2 ((𝑥𝐴𝐶):𝐴1-1𝐵 ↔ ((𝑥𝐴𝐶):𝐴𝐵 ∧ ∀𝑥𝐴𝑦𝐴 (((𝑥𝐴𝐶)‘𝑥) = ((𝑥𝐴𝐶)‘𝑦) → 𝑥 = 𝑦)))
415, 37, 40sylanbrc 402 1 (𝜑 → (𝑥𝐴𝐶):𝐴1-1𝐵)
 Colors of variables: wff set class Syntax hints:   → wi 4   ∧ wa 101   ↔ wb 102   = wceq 1259   ∈ wcel 1409  ∀wral 2323   ↦ cmpt 3845  ⟶wf 4925  –1-1→wf1 4926  ‘cfv 4929 This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 103  ax-ia2 104  ax-ia3 105  ax-io 640  ax-5 1352  ax-7 1353  ax-gen 1354  ax-ie1 1398  ax-ie2 1399  ax-8 1411  ax-10 1412  ax-11 1413  ax-i12 1414  ax-bndl 1415  ax-4 1416  ax-14 1421  ax-17 1435  ax-i9 1439  ax-ial 1443  ax-i5r 1444  ax-ext 2038  ax-sep 3902  ax-pow 3954  ax-pr 3971 This theorem depends on definitions:  df-bi 114  df-3an 898  df-tru 1262  df-nf 1366  df-sb 1662  df-eu 1919  df-mo 1920  df-clab 2043  df-cleq 2049  df-clel 2052  df-nfc 2183  df-ral 2328  df-rex 2329  df-rab 2332  df-v 2576  df-sbc 2787  df-csb 2880  df-un 2949  df-in 2951  df-ss 2958  df-pw 3388  df-sn 3408  df-pr 3409  df-op 3411  df-uni 3608  df-br 3792  df-opab 3846  df-mpt 3847  df-id 4057  df-xp 4378  df-rel 4379  df-cnv 4380  df-co 4381  df-dm 4382  df-rn 4383  df-res 4384  df-ima 4385  df-iota 4894  df-fun 4931  df-fn 4932  df-f 4933  df-f1 4934  df-fv 4937 This theorem is referenced by:  dom2d  6283  dom3d  6284
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