| Metamath Proof Explorer |
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Related theorems GIF version |
| Description: A syllogism rule of inference. The second premise is used to replace the second antecedent of the first premise. |
| Ref | Expression |
|---|---|
| syl5.1 | ⊢ (φ → (ψ → χ)) |
| syl5.2 | ⊢ (θ → ψ) |
| Ref | Expression |
|---|---|
| syl5 | ⊢ (φ → (θ → χ)) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | syl5.1 | . 2 ⊢ (φ → (ψ → χ)) | |
| 2 | syl5.2 | . . 3 ⊢ (θ → ψ) | |
| 3 | 2 | syl4 19 | . 2 ⊢ ((ψ → χ) → (θ → χ)) |
| 4 | 1, 3 | syl 12 | 1 ⊢ (φ → (θ → χ)) |