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| Mirrors > Home > ILE Home > Th. List > alinexa | GIF version | ||
| Description: A transformation of quantifiers and logical connectives. (Contributed by NM, 19-Aug-1993.) |
| Ref | Expression |
|---|---|
| alinexa | ⊢ (∀𝑥(𝜑 → ¬ 𝜓) ↔ ¬ ∃𝑥(𝜑 ∧ 𝜓)) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | imnan 656 | . . 3 ⊢ ((𝜑 → ¬ 𝜓) ↔ ¬ (𝜑 ∧ 𝜓)) | |
| 2 | 1 | albii 1399 | . 2 ⊢ (∀𝑥(𝜑 → ¬ 𝜓) ↔ ∀𝑥 ¬ (𝜑 ∧ 𝜓)) |
| 3 | alnex 1428 | . 2 ⊢ (∀𝑥 ¬ (𝜑 ∧ 𝜓) ↔ ¬ ∃𝑥(𝜑 ∧ 𝜓)) | |
| 4 | 2, 3 | bitri 182 | 1 ⊢ (∀𝑥(𝜑 → ¬ 𝜓) ↔ ¬ ∃𝑥(𝜑 ∧ 𝜓)) |
| Colors of variables: wff set class |
| Syntax hints: ¬ wn 3 → wi 4 ∧ wa 102 ↔ wb 103 ∀wal 1282 ∃wex 1421 |
| This theorem was proved from axioms: ax-1 5 ax-2 6 ax-mp 7 ax-ia1 104 ax-ia2 105 ax-ia3 106 ax-in1 576 ax-in2 577 ax-5 1376 ax-gen 1378 ax-ie2 1423 |
| This theorem depends on definitions: df-bi 115 df-tru 1287 df-fal 1290 |
| This theorem is referenced by: sbnv 1809 ralnex 2358 |
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