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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 3899 | . 2 ⊢ (𝐴 ∈ (𝐵 ∩ 𝐶) ↔ (𝐴 ∈ 𝐵 ∧ 𝐴 ∈ 𝐶)) | |
| 2 | fvi 6904 | . . . . 5 ⊢ (𝐴 ∈ 𝐵 → ( I ‘𝐴) = 𝐴) | |
| 3 | 2 | eqcomd 2745 | . . . 4 ⊢ (𝐴 ∈ 𝐵 → 𝐴 = ( I ‘𝐴)) |
| 4 | 3 | eleq1d 2824 | . . 3 ⊢ (𝐴 ∈ 𝐵 → (𝐴 ∈ 𝐶 ↔ ( I ‘𝐴) ∈ 𝐶)) |
| 5 | 4 | pm5.32i 579 | . 2 ⊢ ((𝐴 ∈ 𝐵 ∧ 𝐴 ∈ 𝐶) ↔ (𝐴 ∈ 𝐵 ∧ ( I ‘𝐴) ∈ 𝐶)) |
| 6 | 1, 5 | bitri 276 | 1 ⊢ (𝐴 ∈ (𝐵 ∩ 𝐶) ↔ (𝐴 ∈ 𝐵 ∧ ( I ‘𝐴) ∈ 𝐶)) |
| Colors of variables: wff setvar class |
| Syntax hints: ↔ wb 207 ∧ wa 396 ∈ wcel 2119 ∩ cin 3882 I cid 5513 ‘cfv 6486 |
| This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1802 ax-4 1816 ax-5 1917 ax-6 1974 ax-7 2015 ax-8 2121 ax-9 2129 ax-10 2152 ax-12 2189 ax-ext 2711 ax-sep 5219 ax-pr 5363 |
| This theorem depends on definitions: df-bi 208 df-an 397 df-or 854 df-3an 1094 df-tru 1550 df-fal 1560 df-ex 1787 df-nf 1791 df-sb 2074 df-mo 2543 df-eu 2573 df-clab 2718 df-cleq 2731 df-clel 2814 df-ral 3054 df-rex 3064 df-rab 3392 df-v 3433 df-dif 3886 df-un 3888 df-in 3890 df-ss 3900 df-nul 4263 df-if 4456 df-sn 4557 df-pr 4559 df-op 4563 df-uni 4840 df-br 5074 df-opab 5136 df-id 5514 df-xp 5625 df-rel 5626 df-cnv 5627 df-co 5628 df-dm 5629 df-iota 6442 df-fun 6488 df-fv 6494 |
| This theorem is referenced by: elcnvcnvlem 44052 |
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