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Mirrors > Home > NFE Home > Th. List > ceqsrexbv | GIF version |
Description: Elimination of a restricted existential quantifier, using implicit substitution. (Contributed by Mario Carneiro, 14-Mar-2014.) |
Ref | Expression |
---|---|
ceqsrexv.1 | ⊢ (x = A → (φ ↔ ψ)) |
Ref | Expression |
---|---|
ceqsrexbv | ⊢ (∃x ∈ B (x = A ∧ φ) ↔ (A ∈ B ∧ ψ)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | r19.42v 2766 | . 2 ⊢ (∃x ∈ B (A ∈ B ∧ (x = A ∧ φ)) ↔ (A ∈ B ∧ ∃x ∈ B (x = A ∧ φ))) | |
2 | eleq1 2413 | . . . . . . 7 ⊢ (x = A → (x ∈ B ↔ A ∈ B)) | |
3 | 2 | adantr 451 | . . . . . 6 ⊢ ((x = A ∧ φ) → (x ∈ B ↔ A ∈ B)) |
4 | 3 | pm5.32ri 619 | . . . . 5 ⊢ ((x ∈ B ∧ (x = A ∧ φ)) ↔ (A ∈ B ∧ (x = A ∧ φ))) |
5 | 4 | bicomi 193 | . . . 4 ⊢ ((A ∈ B ∧ (x = A ∧ φ)) ↔ (x ∈ B ∧ (x = A ∧ φ))) |
6 | 5 | baib 871 | . . 3 ⊢ (x ∈ B → ((A ∈ B ∧ (x = A ∧ φ)) ↔ (x = A ∧ φ))) |
7 | 6 | rexbiia 2648 | . 2 ⊢ (∃x ∈ B (A ∈ B ∧ (x = A ∧ φ)) ↔ ∃x ∈ B (x = A ∧ φ)) |
8 | ceqsrexv.1 | . . . 4 ⊢ (x = A → (φ ↔ ψ)) | |
9 | 8 | ceqsrexv 2973 | . . 3 ⊢ (A ∈ B → (∃x ∈ B (x = A ∧ φ) ↔ ψ)) |
10 | 9 | pm5.32i 618 | . 2 ⊢ ((A ∈ B ∧ ∃x ∈ B (x = A ∧ φ)) ↔ (A ∈ B ∧ ψ)) |
11 | 1, 7, 10 | 3bitr3i 266 | 1 ⊢ (∃x ∈ B (x = A ∧ φ) ↔ (A ∈ B ∧ ψ)) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ↔ wb 176 ∧ wa 358 = wceq 1642 ∈ wcel 1710 ∃wrex 2616 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1546 ax-5 1557 ax-17 1616 ax-9 1654 ax-8 1675 ax-6 1729 ax-7 1734 ax-11 1746 ax-12 1925 ax-ext 2334 |
This theorem depends on definitions: df-bi 177 df-or 359 df-an 360 df-tru 1319 df-ex 1542 df-nf 1545 df-sb 1649 df-clab 2340 df-cleq 2346 df-clel 2349 df-nfc 2479 df-rex 2621 df-v 2862 |
This theorem is referenced by: (None) |
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