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| Mirrors > Home > ILE Home > Th. List > rexrn | GIF version | ||
| Description: Restricted existential quantification over the range of a function. (Contributed by Mario Carneiro, 24-Dec-2013.) (Revised by Mario Carneiro, 20-Aug-2014.) |
| Ref | Expression |
|---|---|
| rexrn.1 | ⊢ (𝑥 = (𝐹‘𝑦) → (𝜑 ↔ 𝜓)) |
| Ref | Expression |
|---|---|
| rexrn | ⊢ (𝐹 Fn 𝐴 → (∃𝑥 ∈ ran 𝐹𝜑 ↔ ∃𝑦 ∈ 𝐴 𝜓)) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | funfvex 5605 | . . 3 ⊢ ((Fun 𝐹 ∧ 𝑦 ∈ dom 𝐹) → (𝐹‘𝑦) ∈ V) | |
| 2 | 1 | funfni 5384 | . 2 ⊢ ((𝐹 Fn 𝐴 ∧ 𝑦 ∈ 𝐴) → (𝐹‘𝑦) ∈ V) |
| 3 | fvelrnb 5638 | . . 3 ⊢ (𝐹 Fn 𝐴 → (𝑥 ∈ ran 𝐹 ↔ ∃𝑦 ∈ 𝐴 (𝐹‘𝑦) = 𝑥)) | |
| 4 | eqcom 2208 | . . . 4 ⊢ ((𝐹‘𝑦) = 𝑥 ↔ 𝑥 = (𝐹‘𝑦)) | |
| 5 | 4 | rexbii 2514 | . . 3 ⊢ (∃𝑦 ∈ 𝐴 (𝐹‘𝑦) = 𝑥 ↔ ∃𝑦 ∈ 𝐴 𝑥 = (𝐹‘𝑦)) |
| 6 | 3, 5 | bitrdi 196 | . 2 ⊢ (𝐹 Fn 𝐴 → (𝑥 ∈ ran 𝐹 ↔ ∃𝑦 ∈ 𝐴 𝑥 = (𝐹‘𝑦))) |
| 7 | rexrn.1 | . . 3 ⊢ (𝑥 = (𝐹‘𝑦) → (𝜑 ↔ 𝜓)) | |
| 8 | 7 | adantl 277 | . 2 ⊢ ((𝐹 Fn 𝐴 ∧ 𝑥 = (𝐹‘𝑦)) → (𝜑 ↔ 𝜓)) |
| 9 | 2, 6, 8 | rexxfr2d 4519 | 1 ⊢ (𝐹 Fn 𝐴 → (∃𝑥 ∈ ran 𝐹𝜑 ↔ ∃𝑦 ∈ 𝐴 𝜓)) |
| Colors of variables: wff set class |
| Syntax hints: → wi 4 ↔ wb 105 = wceq 1373 ∈ wcel 2177 ∃wrex 2486 Vcvv 2773 ran crn 4683 Fn wfn 5274 ‘cfv 5279 |
| This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-ia1 106 ax-ia2 107 ax-ia3 108 ax-io 711 ax-5 1471 ax-7 1472 ax-gen 1473 ax-ie1 1517 ax-ie2 1518 ax-8 1528 ax-10 1529 ax-11 1530 ax-i12 1531 ax-bndl 1533 ax-4 1534 ax-17 1550 ax-i9 1554 ax-ial 1558 ax-i5r 1559 ax-14 2180 ax-ext 2188 ax-sep 4169 ax-pow 4225 ax-pr 4260 |
| This theorem depends on definitions: df-bi 117 df-3an 983 df-tru 1376 df-nf 1485 df-sb 1787 df-eu 2058 df-mo 2059 df-clab 2193 df-cleq 2199 df-clel 2202 df-nfc 2338 df-ral 2490 df-rex 2491 df-v 2775 df-sbc 3003 df-un 3174 df-in 3176 df-ss 3183 df-pw 3622 df-sn 3643 df-pr 3644 df-op 3646 df-uni 3856 df-br 4051 df-opab 4113 df-mpt 4114 df-id 4347 df-xp 4688 df-rel 4689 df-cnv 4690 df-co 4691 df-dm 4692 df-rn 4693 df-iota 5240 df-fun 5281 df-fn 5282 df-fv 5287 |
| This theorem is referenced by: elrnrexdm 5731 rexrnmpt 5735 cbvexfo 5867 rexanuz 11369 znunit 14491 lmbr2 14756 lmff 14791 |
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