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| Mirrors > Home > MPE Home > Th. List > rescnvimafod | Structured version Visualization version GIF version | ||
| Description: The restriction of a function to a preimage of a class is a function onto the intersection of this class and the range of the function. (Contributed by AV, 13-Sep-2024.) (Revised by AV, 29-Sep-2024.) |
| Ref | Expression |
|---|---|
| rescnvimafod.f | ⊢ (𝜑 → 𝐹 Fn 𝐴) |
| rescnvimafod.e | ⊢ (𝜑 → 𝐸 = (ran 𝐹 ∩ 𝐵)) |
| rescnvimafod.d | ⊢ (𝜑 → 𝐷 = (◡𝐹 “ 𝐵)) |
| Ref | Expression |
|---|---|
| rescnvimafod | ⊢ (𝜑 → (𝐹 ↾ 𝐷):𝐷–onto→𝐸) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | rescnvimafod.f | . . 3 ⊢ (𝜑 → 𝐹 Fn 𝐴) | |
| 2 | cnvimass 6089 | . . . . 5 ⊢ (◡𝐹 “ 𝐵) ⊆ dom 𝐹 | |
| 3 | 2 | a1i 11 | . . . 4 ⊢ (𝜑 → (◡𝐹 “ 𝐵) ⊆ dom 𝐹) |
| 4 | rescnvimafod.d | . . . 4 ⊢ (𝜑 → 𝐷 = (◡𝐹 “ 𝐵)) | |
| 5 | 1 | fndmd 6647 | . . . . 5 ⊢ (𝜑 → dom 𝐹 = 𝐴) |
| 6 | 5 | eqcomd 2772 | . . . 4 ⊢ (𝜑 → 𝐴 = dom 𝐹) |
| 7 | 3, 4, 6 | 3sstr4d 3995 | . . 3 ⊢ (𝜑 → 𝐷 ⊆ 𝐴) |
| 8 | 1, 7 | fnssresd 6666 | . 2 ⊢ (𝜑 → (𝐹 ↾ 𝐷) Fn 𝐷) |
| 9 | df-ima 5679 | . . . 4 ⊢ (𝐹 “ 𝐷) = ran (𝐹 ↾ 𝐷) | |
| 10 | 4 | imaeq2d 6067 | . . . . 5 ⊢ (𝜑 → (𝐹 “ 𝐷) = (𝐹 “ (◡𝐹 “ 𝐵))) |
| 11 | fnfun 6642 | . . . . . 6 ⊢ (𝐹 Fn 𝐴 → Fun 𝐹) | |
| 12 | funimacnv 6624 | . . . . . 6 ⊢ (Fun 𝐹 → (𝐹 “ (◡𝐹 “ 𝐵)) = (𝐵 ∩ ran 𝐹)) | |
| 13 | 1, 11, 12 | 3syl 19 | . . . . 5 ⊢ (𝜑 → (𝐹 “ (◡𝐹 “ 𝐵)) = (𝐵 ∩ ran 𝐹)) |
| 14 | incom 4165 | . . . . . 6 ⊢ (𝐵 ∩ ran 𝐹) = (ran 𝐹 ∩ 𝐵) | |
| 15 | 14 | a1i 11 | . . . . 5 ⊢ (𝜑 → (𝐵 ∩ ran 𝐹) = (ran 𝐹 ∩ 𝐵)) |
| 16 | 10, 13, 15 | 3eqtrd 2805 | . . . 4 ⊢ (𝜑 → (𝐹 “ 𝐷) = (ran 𝐹 ∩ 𝐵)) |
| 17 | 9, 16 | eqtr3id 2815 | . . 3 ⊢ (𝜑 → ran (𝐹 ↾ 𝐷) = (ran 𝐹 ∩ 𝐵)) |
| 18 | rescnvimafod.e | . . 3 ⊢ (𝜑 → 𝐸 = (ran 𝐹 ∩ 𝐵)) | |
| 19 | 17, 18 | eqtr4d 2804 | . 2 ⊢ (𝜑 → ran (𝐹 ↾ 𝐷) = 𝐸) |
| 20 | df-fo 6549 | . 2 ⊢ ((𝐹 ↾ 𝐷):𝐷–onto→𝐸 ↔ ((𝐹 ↾ 𝐷) Fn 𝐷 ∧ ran (𝐹 ↾ 𝐷) = 𝐸)) | |
| 21 | 8, 19, 20 | sylanbrc 595 | 1 ⊢ (𝜑 → (𝐹 ↾ 𝐷):𝐷–onto→𝐸) |
| Colors of variables: wff setvar class |
| This proof depends on syntax axioms: → wi 4 = wceq 1570 ∩ cin 3907 ⊆ wss 3908 ◡ccnv 5665 dom cdm 5666 ran crn 5667 ↾ cres 5668 “ cima 5669 Fun wfun 6537 Fn wfn 6538 –onto→wfo 6541 |
| This proof depends on axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1828 ax-4 1842 ax-5 1943 ax-6 2000 ax-7 2041 ax-8 2148 ax-9 2156 ax-12 2216 ax-ext 2738 ax-sep 5262 ax-pr 5409 |
| This proof depends on definitions: df-bi 210 df-an 402 df-or 862 df-3an 1105 df-tru 1573 df-fal 1583 df-ex 1813 df-sb 2100 df-mo 2570 df-eu 2600 df-clab 2745 df-cleq 2758 df-clel 2841 df-ral 3083 df-rex 3093 df-rab 3420 df-v 3460 df-dif 3911 df-un 3913 df-in 3915 df-ss 3925 df-nul 4290 df-if 4493 df-sn 4595 df-pr 4597 df-op 4601 df-br 5115 df-opab 5179 df-id 5561 df-xp 5672 df-rel 5673 df-cnv 5674 df-co 5675 df-dm 5676 df-rn 5677 df-res 5678 df-ima 5679 df-fun 6545 df-fn 6546 df-fo 6549 |
| This theorem is used by: fresfo 47826 fcoreslem3 47843 3f1oss1 47853 |
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