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Mirrors > Home > NFE Home > Th. List > nanim | GIF version |
Description: Show equivalence between implication and the Nicod version. To derive nic-dfim 1434, apply nanbi 1294. (Contributed by Jeff Hoffman, 19-Nov-2007.) |
Ref | Expression |
---|---|
nanim | ⊢ ((φ → ψ) ↔ (φ ⊼ (ψ ⊼ ψ))) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | nannan 1291 | . 2 ⊢ ((φ ⊼ (ψ ⊼ ψ)) ↔ (φ → (ψ ∧ ψ))) | |
2 | anidmdbi 627 | . 2 ⊢ ((φ → (ψ ∧ ψ)) ↔ (φ → ψ)) | |
3 | 1, 2 | bitr2i 241 | 1 ⊢ ((φ → ψ) ↔ (φ ⊼ (ψ ⊼ ψ))) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ↔ wb 176 ∧ wa 358 ⊼ wnan 1287 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 |
This theorem depends on definitions: df-bi 177 df-an 360 df-nan 1288 |
This theorem is referenced by: nic-dfim 1434 nic-ax 1438 |
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