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Mirrors > Home > MPE Home > Th. List > cofunex2g | Structured version Visualization version GIF version |
Description: Existence of a composition when the second member is one-to-one. (Contributed by NM, 8-Oct-2007.) |
Ref | Expression |
---|---|
cofunex2g | ⊢ ((𝐴 ∈ 𝑉 ∧ Fun ◡𝐵) → (𝐴 ∘ 𝐵) ∈ V) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | cnvexg 7930 | . . . 4 ⊢ (𝐴 ∈ 𝑉 → ◡𝐴 ∈ V) | |
2 | cofunexg 7950 | . . . 4 ⊢ ((Fun ◡𝐵 ∧ ◡𝐴 ∈ V) → (◡𝐵 ∘ ◡𝐴) ∈ V) | |
3 | 1, 2 | sylan2 591 | . . 3 ⊢ ((Fun ◡𝐵 ∧ 𝐴 ∈ 𝑉) → (◡𝐵 ∘ ◡𝐴) ∈ V) |
4 | cnvco 5882 | . . . . 5 ⊢ ◡(◡𝐵 ∘ ◡𝐴) = (◡◡𝐴 ∘ ◡◡𝐵) | |
5 | cocnvcnv2 6257 | . . . . 5 ⊢ (◡◡𝐴 ∘ ◡◡𝐵) = (◡◡𝐴 ∘ 𝐵) | |
6 | cocnvcnv1 6256 | . . . . 5 ⊢ (◡◡𝐴 ∘ 𝐵) = (𝐴 ∘ 𝐵) | |
7 | 4, 5, 6 | 3eqtrri 2758 | . . . 4 ⊢ (𝐴 ∘ 𝐵) = ◡(◡𝐵 ∘ ◡𝐴) |
8 | cnvexg 7930 | . . . 4 ⊢ ((◡𝐵 ∘ ◡𝐴) ∈ V → ◡(◡𝐵 ∘ ◡𝐴) ∈ V) | |
9 | 7, 8 | eqeltrid 2829 | . . 3 ⊢ ((◡𝐵 ∘ ◡𝐴) ∈ V → (𝐴 ∘ 𝐵) ∈ V) |
10 | 3, 9 | syl 17 | . 2 ⊢ ((Fun ◡𝐵 ∧ 𝐴 ∈ 𝑉) → (𝐴 ∘ 𝐵) ∈ V) |
11 | 10 | ancoms 457 | 1 ⊢ ((𝐴 ∈ 𝑉 ∧ Fun ◡𝐵) → (𝐴 ∘ 𝐵) ∈ V) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ∧ wa 394 ∈ wcel 2098 Vcvv 3463 ◡ccnv 5671 ∘ ccom 5676 Fun wfun 6537 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1789 ax-4 1803 ax-5 1905 ax-6 1963 ax-7 2003 ax-8 2100 ax-9 2108 ax-10 2129 ax-11 2146 ax-12 2166 ax-ext 2696 ax-rep 5280 ax-sep 5294 ax-nul 5301 ax-pow 5359 ax-pr 5423 ax-un 7738 |
This theorem depends on definitions: df-bi 206 df-an 395 df-or 846 df-3an 1086 df-tru 1536 df-fal 1546 df-ex 1774 df-nf 1778 df-sb 2060 df-mo 2528 df-eu 2557 df-clab 2703 df-cleq 2717 df-clel 2802 df-nfc 2877 df-ne 2931 df-ral 3052 df-rex 3061 df-reu 3365 df-rab 3420 df-v 3465 df-sbc 3769 df-csb 3885 df-dif 3942 df-un 3944 df-in 3946 df-ss 3956 df-nul 4319 df-if 4525 df-pw 4600 df-sn 4625 df-pr 4627 df-op 4631 df-uni 4904 df-iun 4993 df-br 5144 df-opab 5206 df-mpt 5227 df-id 5570 df-xp 5678 df-rel 5679 df-cnv 5680 df-co 5681 df-dm 5682 df-rn 5683 df-res 5684 df-ima 5685 df-iota 6495 df-fun 6545 df-fn 6546 df-f 6547 df-f1 6548 df-fo 6549 df-f1o 6550 df-fv 6551 |
This theorem is referenced by: fsuppco 9425 |
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