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Mirrors > Home > NFE Home > Th. List > rspc3ev | GIF version |
Description: 3-variable restricted existentional specialization, using implicit substitution. (Contributed by NM, 25-Jul-2012.) |
Ref | Expression |
---|---|
rspc3v.1 | ⊢ (x = A → (φ ↔ χ)) |
rspc3v.2 | ⊢ (y = B → (χ ↔ θ)) |
rspc3v.3 | ⊢ (z = C → (θ ↔ ψ)) |
Ref | Expression |
---|---|
rspc3ev | ⊢ (((A ∈ R ∧ B ∈ S ∧ C ∈ T) ∧ ψ) → ∃x ∈ R ∃y ∈ S ∃z ∈ T φ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | simpl1 958 | . 2 ⊢ (((A ∈ R ∧ B ∈ S ∧ C ∈ T) ∧ ψ) → A ∈ R) | |
2 | simpl2 959 | . 2 ⊢ (((A ∈ R ∧ B ∈ S ∧ C ∈ T) ∧ ψ) → B ∈ S) | |
3 | rspc3v.3 | . . . 4 ⊢ (z = C → (θ ↔ ψ)) | |
4 | 3 | rspcev 2956 | . . 3 ⊢ ((C ∈ T ∧ ψ) → ∃z ∈ T θ) |
5 | 4 | 3ad2antl3 1119 | . 2 ⊢ (((A ∈ R ∧ B ∈ S ∧ C ∈ T) ∧ ψ) → ∃z ∈ T θ) |
6 | rspc3v.1 | . . . 4 ⊢ (x = A → (φ ↔ χ)) | |
7 | 6 | rexbidv 2636 | . . 3 ⊢ (x = A → (∃z ∈ T φ ↔ ∃z ∈ T χ)) |
8 | rspc3v.2 | . . . 4 ⊢ (y = B → (χ ↔ θ)) | |
9 | 8 | rexbidv 2636 | . . 3 ⊢ (y = B → (∃z ∈ T χ ↔ ∃z ∈ T θ)) |
10 | 7, 9 | rspc2ev 2964 | . 2 ⊢ ((A ∈ R ∧ B ∈ S ∧ ∃z ∈ T θ) → ∃x ∈ R ∃y ∈ S ∃z ∈ T φ) |
11 | 1, 2, 5, 10 | syl3anc 1182 | 1 ⊢ (((A ∈ R ∧ B ∈ S ∧ C ∈ T) ∧ ψ) → ∃x ∈ R ∃y ∈ S ∃z ∈ T φ) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ↔ wb 176 ∧ wa 358 ∧ w3a 934 = 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-3an 936 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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