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Related theorems GIF version |
| Description: Lemma for rederiving standard propositional axioms from Lukasiewicz'. |
| Ref | Expression |
|---|---|
| luklem1.1 | ⊢ (φ → ψ) |
| luklem1.2 | ⊢ (ψ → χ) |
| Ref | Expression |
|---|---|
| luklem1 | ⊢ (φ → χ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | luklem1.2 | . 2 ⊢ (ψ → χ) | |
| 2 | luklem1.1 | . . 3 ⊢ (φ → ψ) | |
| 3 | luk-1 658 | . . 3 ⊢ ((φ → ψ) → ((ψ → χ) → (φ → χ))) | |
| 4 | 2, 3 | ax-mp 6 | . 2 ⊢ ((ψ → χ) → (φ → χ)) |
| 5 | 1, 4 | ax-mp 6 | 1 ⊢ (φ → χ) |
| Colors of variables: wff set class |
| Syntax hints: → wi 2 |
| This theorem is referenced by: luklem2 662 luklem3 663 luklem4 664 luklem5 665 luklem6 666 luklem7 667 ax2 670 ax3 671 |
| This theorem was proved from axioms: ax-1 3 ax-2 4 ax-3 5 ax-mp 6 |