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Related theorems GIF version |
| Description: Deduction joining two equivalences to form equivalence of conjunctions. |
| Ref | Expression |
|---|---|
| bi12d.1 | ⊢ (φ → (ψ ↔ χ)) |
| bi12d.2 | ⊢ (φ → (θ ↔ τ)) |
| Ref | Expression |
|---|---|
| anbi12d | ⊢ (φ → ((ψ ⋀ θ) ↔ (χ ⋀ τ))) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | bi12d.1 | . . 3 ⊢ (φ → (ψ ↔ χ)) | |
| 2 | 1 | anbi1d 620 | . 2 ⊢ (φ → ((ψ ⋀ θ) ↔ (χ ⋀ θ))) |
| 3 | bi12d.2 | . . 3 ⊢ (φ → (θ ↔ τ)) | |
| 4 | 3 | anbi2d 619 | . 2 ⊢ (φ → ((χ ⋀ θ) ↔ (χ ⋀ τ))) |
| 5 | 2, 4 | bitrd 531 | 1 ⊢ (φ → ((ψ ⋀ θ) ↔ (χ ⋀ τ))) |