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| Mirrors > Home > MPE Home > Th. List > Mathboxes > elinlem | Structured version Visualization version GIF version | ||
| Description: Two ways to say a set is a member of an intersection. (Contributed by RP, 19-Aug-2020.) |
| Ref | Expression |
|---|---|
| elinlem | ⊢ (𝐴 ∈ (𝐵 ∩ 𝐶) ↔ (𝐴 ∈ 𝐵 ∧ ( I ‘𝐴) ∈ 𝐶)) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | elin 3949 | . 2 ⊢ (𝐴 ∈ (𝐵 ∩ 𝐶) ↔ (𝐴 ∈ 𝐵 ∧ 𝐴 ∈ 𝐶)) | |
| 2 | fvi 6966 | . . . . 5 ⊢ (𝐴 ∈ 𝐵 → ( I ‘𝐴) = 𝐴) | |
| 3 | 2 | eqcomd 2740 | . . . 4 ⊢ (𝐴 ∈ 𝐵 → 𝐴 = ( I ‘𝐴)) |
| 4 | 3 | eleq1d 2818 | . . 3 ⊢ (𝐴 ∈ 𝐵 → (𝐴 ∈ 𝐶 ↔ ( I ‘𝐴) ∈ 𝐶)) |
| 5 | 4 | pm5.32i 574 | . 2 ⊢ ((𝐴 ∈ 𝐵 ∧ 𝐴 ∈ 𝐶) ↔ (𝐴 ∈ 𝐵 ∧ ( I ‘𝐴) ∈ 𝐶)) |
| 6 | 1, 5 | bitri 275 | 1 ⊢ (𝐴 ∈ (𝐵 ∩ 𝐶) ↔ (𝐴 ∈ 𝐵 ∧ ( I ‘𝐴) ∈ 𝐶)) |
| Colors of variables: wff setvar class |
| Syntax hints: ↔ wb 206 ∧ wa 395 ∈ wcel 2107 ∩ cin 3932 I cid 5559 ‘cfv 6542 |
| This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1794 ax-4 1808 ax-5 1909 ax-6 1966 ax-7 2006 ax-8 2109 ax-9 2117 ax-10 2140 ax-12 2176 ax-ext 2706 ax-sep 5278 ax-nul 5288 ax-pr 5414 |
| This theorem depends on definitions: df-bi 207 df-an 396 df-or 848 df-3an 1088 df-tru 1542 df-fal 1552 df-ex 1779 df-nf 1783 df-sb 2064 df-mo 2538 df-eu 2567 df-clab 2713 df-cleq 2726 df-clel 2808 df-ral 3051 df-rex 3060 df-rab 3421 df-v 3466 df-dif 3936 df-un 3938 df-in 3940 df-ss 3950 df-nul 4316 df-if 4508 df-sn 4609 df-pr 4611 df-op 4615 df-uni 4890 df-br 5126 df-opab 5188 df-id 5560 df-xp 5673 df-rel 5674 df-cnv 5675 df-co 5676 df-dm 5677 df-iota 6495 df-fun 6544 df-fv 6550 |
| This theorem is referenced by: elcnvcnvlem 43557 |
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