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Related theorems GIF version |
| Description: Syllogism inference. (A bit of trivia: this is the most commonly referenced assertion in our database. In second place is ax-mp 6, followed by visset 1350, bitr 151, imp 277, and exp 291. The Metamath program command 'show usage' shows the number of references.) |
| Ref | Expression |
|---|---|
| syl.1 | ⊢ (φ → ψ) |
| syl.2 | ⊢ (ψ → χ) |
| Ref | Expression |
|---|---|
| syl | ⊢ (φ → χ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | syl.1 | . 2 ⊢ (φ → ψ) | |
| 2 | syl.2 | . . . 4 ⊢ (ψ → χ) | |
| 3 | 2 | a1i 7 | . . 3 ⊢ (φ → (ψ → χ)) |
| 4 | 3 | a2i 8 | . 2 ⊢ ((φ → ψ) → (φ → χ)) |
| 5 | 1, 4 | ax-mp 6 | 1 ⊢ (φ → χ) |