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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 3921 | . 2 ⊢ (𝐴 ∈ (𝐵 ∩ 𝐶) ↔ (𝐴 ∈ 𝐵 ∧ 𝐴 ∈ 𝐶)) | |
| 2 | fvi 6944 | . . . . 5 ⊢ (𝐴 ∈ 𝐵 → ( I ‘𝐴) = 𝐴) | |
| 3 | 2 | eqcomd 2769 | . . . 4 ⊢ (𝐴 ∈ 𝐵 → 𝐴 = ( I ‘𝐴)) |
| 4 | 3 | eleq1d 2848 | . . 3 ⊢ (𝐴 ∈ 𝐵 → (𝐴 ∈ 𝐶 ↔ ( I ‘𝐴) ∈ 𝐶)) |
| 5 | 4 | pm5.32i 582 | . 2 ⊢ ((𝐴 ∈ 𝐵 ∧ 𝐴 ∈ 𝐶) ↔ (𝐴 ∈ 𝐵 ∧ ( I ‘𝐴) ∈ 𝐶)) |
| 6 | 1, 5 | bitri 277 | 1 ⊢ (𝐴 ∈ (𝐵 ∩ 𝐶) ↔ (𝐴 ∈ 𝐵 ∧ ( I ‘𝐴) ∈ 𝐶)) |
| Colors of variables: wff setvar class |
| Syntax hints: ↔ wb 208 ∧ wa 399 ∈ wcel 2143 ∩ cin 3904 I cid 5542 ‘cfv 6522 |
| This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1816 ax-4 1830 ax-5 1931 ax-6 1988 ax-7 2029 ax-8 2145 ax-9 2153 ax-10 2176 ax-12 2213 ax-ext 2735 ax-sep 5247 ax-pr 5391 |
| This theorem depends on definitions: df-bi 209 df-an 400 df-or 859 df-3an 1101 df-tru 1564 df-fal 1574 df-ex 1801 df-nf 1805 df-sb 2092 df-mo 2567 df-eu 2597 df-clab 2742 df-cleq 2755 df-clel 2838 df-ral 3078 df-rex 3088 df-rab 3416 df-v 3457 df-dif 3908 df-un 3910 df-in 3912 df-ss 3922 df-nul 4287 df-if 4482 df-sn 4584 df-pr 4586 df-op 4590 df-uni 4867 df-br 5102 df-opab 5164 df-id 5543 df-xp 5654 df-rel 5655 df-cnv 5656 df-co 5657 df-dm 5658 df-iota 6478 df-fun 6524 df-fv 6530 |
| This theorem is referenced by: elcnvcnvlem 44176 |
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