![]() |
Metamath Proof Explorer |
< Previous
Next >
Nearby theorems |
|
Mirrors > Home > MPE Home > Th. List > nfrexd | Structured version Visualization version GIF version |
Description: Deduction version of nfrex 3368. Usage of this theorem is discouraged because it depends on ax-13 2367. See nfrexdw 3304 for a version with a disjoint variable condition, but not requiring ax-13 2367. (Contributed by Mario Carneiro, 14-Oct-2016.) (New usage is discouraged.) |
Ref | Expression |
---|---|
nfrald.1 | ⊢ Ⅎ𝑦𝜑 |
nfrald.2 | ⊢ (𝜑 → Ⅎ𝑥𝐴) |
nfrald.3 | ⊢ (𝜑 → Ⅎ𝑥𝜓) |
Ref | Expression |
---|---|
nfrexd | ⊢ (𝜑 → Ⅎ𝑥∃𝑦 ∈ 𝐴 𝜓) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | dfrex2 3070 | . 2 ⊢ (∃𝑦 ∈ 𝐴 𝜓 ↔ ¬ ∀𝑦 ∈ 𝐴 ¬ 𝜓) | |
2 | nfrald.1 | . . . 4 ⊢ Ⅎ𝑦𝜑 | |
3 | nfrald.2 | . . . 4 ⊢ (𝜑 → Ⅎ𝑥𝐴) | |
4 | nfrald.3 | . . . . 5 ⊢ (𝜑 → Ⅎ𝑥𝜓) | |
5 | 4 | nfnd 1854 | . . . 4 ⊢ (𝜑 → Ⅎ𝑥 ¬ 𝜓) |
6 | 2, 3, 5 | nfrald 3365 | . . 3 ⊢ (𝜑 → Ⅎ𝑥∀𝑦 ∈ 𝐴 ¬ 𝜓) |
7 | 6 | nfnd 1854 | . 2 ⊢ (𝜑 → Ⅎ𝑥 ¬ ∀𝑦 ∈ 𝐴 ¬ 𝜓) |
8 | 1, 7 | nfxfrd 1849 | 1 ⊢ (𝜑 → Ⅎ𝑥∃𝑦 ∈ 𝐴 𝜓) |
Colors of variables: wff setvar class |
Syntax hints: ¬ wn 3 → wi 4 Ⅎwnf 1778 Ⅎwnfc 2879 ∀wral 3058 ∃wrex 3067 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1790 ax-4 1804 ax-5 1906 ax-6 1964 ax-7 2004 ax-8 2101 ax-9 2109 ax-10 2130 ax-11 2147 ax-12 2167 ax-13 2367 ax-ext 2699 |
This theorem depends on definitions: df-bi 206 df-an 396 df-or 847 df-tru 1537 df-ex 1775 df-nf 1779 df-cleq 2720 df-clel 2806 df-nfc 2881 df-ral 3059 df-rex 3068 |
This theorem is referenced by: nfrex 3368 nfiundg 48106 |
Copyright terms: Public domain | W3C validator |