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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 6111 | . . . . 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 6684 | . . . . 5 ⊢ (𝜑 → dom 𝐹 = 𝐴) |
6 | 5 | eqcomd 2746 | . . . 4 ⊢ (𝜑 → 𝐴 = dom 𝐹) |
7 | 3, 4, 6 | 3sstr4d 4056 | . . 3 ⊢ (𝜑 → 𝐷 ⊆ 𝐴) |
8 | 1, 7 | fnssresd 6704 | . 2 ⊢ (𝜑 → (𝐹 ↾ 𝐷) Fn 𝐷) |
9 | df-ima 5713 | . . . 4 ⊢ (𝐹 “ 𝐷) = ran (𝐹 ↾ 𝐷) | |
10 | 4 | imaeq2d 6089 | . . . . 5 ⊢ (𝜑 → (𝐹 “ 𝐷) = (𝐹 “ (◡𝐹 “ 𝐵))) |
11 | fnfun 6679 | . . . . . 6 ⊢ (𝐹 Fn 𝐴 → Fun 𝐹) | |
12 | funimacnv 6659 | . . . . . 6 ⊢ (Fun 𝐹 → (𝐹 “ (◡𝐹 “ 𝐵)) = (𝐵 ∩ ran 𝐹)) | |
13 | 1, 11, 12 | 3syl 18 | . . . . 5 ⊢ (𝜑 → (𝐹 “ (◡𝐹 “ 𝐵)) = (𝐵 ∩ ran 𝐹)) |
14 | incom 4230 | . . . . . 6 ⊢ (𝐵 ∩ ran 𝐹) = (ran 𝐹 ∩ 𝐵) | |
15 | 14 | a1i 11 | . . . . 5 ⊢ (𝜑 → (𝐵 ∩ ran 𝐹) = (ran 𝐹 ∩ 𝐵)) |
16 | 10, 13, 15 | 3eqtrd 2784 | . . . 4 ⊢ (𝜑 → (𝐹 “ 𝐷) = (ran 𝐹 ∩ 𝐵)) |
17 | 9, 16 | eqtr3id 2794 | . . 3 ⊢ (𝜑 → ran (𝐹 ↾ 𝐷) = (ran 𝐹 ∩ 𝐵)) |
18 | rescnvimafod.e | . . 3 ⊢ (𝜑 → 𝐸 = (ran 𝐹 ∩ 𝐵)) | |
19 | 17, 18 | eqtr4d 2783 | . 2 ⊢ (𝜑 → ran (𝐹 ↾ 𝐷) = 𝐸) |
20 | df-fo 6579 | . 2 ⊢ ((𝐹 ↾ 𝐷):𝐷–onto→𝐸 ↔ ((𝐹 ↾ 𝐷) Fn 𝐷 ∧ ran (𝐹 ↾ 𝐷) = 𝐸)) | |
21 | 8, 19, 20 | sylanbrc 582 | 1 ⊢ (𝜑 → (𝐹 ↾ 𝐷):𝐷–onto→𝐸) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 = wceq 1537 ∩ cin 3975 ⊆ wss 3976 ◡ccnv 5699 dom cdm 5700 ran crn 5701 ↾ cres 5702 “ cima 5703 Fun wfun 6567 Fn wfn 6568 –onto→wfo 6571 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1793 ax-4 1807 ax-5 1909 ax-6 1967 ax-7 2007 ax-8 2110 ax-9 2118 ax-12 2178 ax-ext 2711 ax-sep 5317 ax-nul 5324 ax-pr 5447 |
This theorem depends on definitions: df-bi 207 df-an 396 df-or 847 df-3an 1089 df-tru 1540 df-fal 1550 df-ex 1778 df-sb 2065 df-mo 2543 df-eu 2572 df-clab 2718 df-cleq 2732 df-clel 2819 df-ral 3068 df-rex 3077 df-rab 3444 df-v 3490 df-dif 3979 df-un 3981 df-in 3983 df-ss 3993 df-nul 4353 df-if 4549 df-sn 4649 df-pr 4651 df-op 4655 df-br 5167 df-opab 5229 df-id 5593 df-xp 5706 df-rel 5707 df-cnv 5708 df-co 5709 df-dm 5710 df-rn 5711 df-res 5712 df-ima 5713 df-fun 6575 df-fn 6576 df-fo 6579 |
This theorem is referenced by: fresfo 46963 fcoreslem3 46980 3f1oss1 46990 |
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