Description: Corollary of commutation of and. (Contributed by RP, 25-Apr-2020)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | ifpancor | ⊢ ( if- ( 𝜑 , 𝜓 , 𝜑 ) ↔ if- ( 𝜓 , 𝜑 , 𝜓 ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | ancom | ⊢ ( ( 𝜑 ∧ 𝜓 ) ↔ ( 𝜓 ∧ 𝜑 ) ) | |
| 2 | ifpdfan2 | ⊢ ( ( 𝜑 ∧ 𝜓 ) ↔ if- ( 𝜑 , 𝜓 , 𝜑 ) ) | |
| 3 | ifpdfan2 | ⊢ ( ( 𝜓 ∧ 𝜑 ) ↔ if- ( 𝜓 , 𝜑 , 𝜓 ) ) | |
| 4 | 1 2 3 | 3bitr3i | ⊢ ( if- ( 𝜑 , 𝜓 , 𝜑 ) ↔ if- ( 𝜓 , 𝜑 , 𝜓 ) ) |