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Mirrors > Home > ILE Home > Th. List > alexnim | GIF version |
Description: A relationship between two quantifiers and negation. (Contributed by Jim Kingdon, 27-Aug-2018.) |
Ref | Expression |
---|---|
alexnim | ⊢ (∀𝑥∃𝑦 ¬ 𝜑 → ¬ ∃𝑥∀𝑦𝜑) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | exnalim 1580 | . . 3 ⊢ (∃𝑦 ¬ 𝜑 → ¬ ∀𝑦𝜑) | |
2 | 1 | alimi 1387 | . 2 ⊢ (∀𝑥∃𝑦 ¬ 𝜑 → ∀𝑥 ¬ ∀𝑦𝜑) |
3 | alnex 1431 | . 2 ⊢ (∀𝑥 ¬ ∀𝑦𝜑 ↔ ¬ ∃𝑥∀𝑦𝜑) | |
4 | 2, 3 | sylib 120 | 1 ⊢ (∀𝑥∃𝑦 ¬ 𝜑 → ¬ ∃𝑥∀𝑦𝜑) |
Colors of variables: wff set class |
Syntax hints: ¬ wn 3 → wi 4 ∀wal 1285 ∃wex 1424 |
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 577 ax-in2 578 ax-5 1379 ax-gen 1381 ax-ie1 1425 ax-ie2 1426 ax-4 1443 ax-17 1462 ax-ial 1470 |
This theorem depends on definitions: df-bi 115 df-tru 1290 df-fal 1293 df-nf 1393 |
This theorem is referenced by: nalset 3937 bj-nalset 11143 |
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