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Mirrors > Home > NFE Home > Th. List > nanan | GIF version |
Description: Write 'and' in terms of 'nand'. (Contributed by Mario Carneiro, 9-May-2015.) |
Ref | Expression |
---|---|
nanan | ⊢ ((φ ∧ ψ) ↔ ¬ (φ ⊼ ψ)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | df-nan 1288 | . 2 ⊢ ((φ ⊼ ψ) ↔ ¬ (φ ∧ ψ)) | |
2 | 1 | con2bii 322 | 1 ⊢ ((φ ∧ ψ) ↔ ¬ (φ ⊼ ψ)) |
Colors of variables: wff setvar class |
Syntax hints: ¬ wn 3 ↔ 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-nan 1288 |
This theorem is referenced by: (None) |
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