| Step | Hyp | Ref | Expression | 
						
							| 1 |  | raleqbidvv.1 | ⊢ ( 𝜑  →  𝐴  =  𝐵 ) | 
						
							| 2 |  | raleqbidvv.2 | ⊢ ( 𝜑  →  ( 𝜓  ↔  𝜒 ) ) | 
						
							| 3 | 2 | alrimiv | ⊢ ( 𝜑  →  ∀ 𝑥 ( 𝜓  ↔  𝜒 ) ) | 
						
							| 4 |  | dfcleq | ⊢ ( 𝐴  =  𝐵  ↔  ∀ 𝑥 ( 𝑥  ∈  𝐴  ↔  𝑥  ∈  𝐵 ) ) | 
						
							| 5 | 1 4 | sylib | ⊢ ( 𝜑  →  ∀ 𝑥 ( 𝑥  ∈  𝐴  ↔  𝑥  ∈  𝐵 ) ) | 
						
							| 6 |  | 19.26 | ⊢ ( ∀ 𝑥 ( ( 𝜓  ↔  𝜒 )  ∧  ( 𝑥  ∈  𝐴  ↔  𝑥  ∈  𝐵 ) )  ↔  ( ∀ 𝑥 ( 𝜓  ↔  𝜒 )  ∧  ∀ 𝑥 ( 𝑥  ∈  𝐴  ↔  𝑥  ∈  𝐵 ) ) ) | 
						
							| 7 | 3 5 6 | sylanbrc | ⊢ ( 𝜑  →  ∀ 𝑥 ( ( 𝜓  ↔  𝜒 )  ∧  ( 𝑥  ∈  𝐴  ↔  𝑥  ∈  𝐵 ) ) ) | 
						
							| 8 |  | imbi12 | ⊢ ( ( 𝑥  ∈  𝐴  ↔  𝑥  ∈  𝐵 )  →  ( ( 𝜓  ↔  𝜒 )  →  ( ( 𝑥  ∈  𝐴  →  𝜓 )  ↔  ( 𝑥  ∈  𝐵  →  𝜒 ) ) ) ) | 
						
							| 9 | 8 | impcom | ⊢ ( ( ( 𝜓  ↔  𝜒 )  ∧  ( 𝑥  ∈  𝐴  ↔  𝑥  ∈  𝐵 ) )  →  ( ( 𝑥  ∈  𝐴  →  𝜓 )  ↔  ( 𝑥  ∈  𝐵  →  𝜒 ) ) ) | 
						
							| 10 | 7 9 | sylg | ⊢ ( 𝜑  →  ∀ 𝑥 ( ( 𝑥  ∈  𝐴  →  𝜓 )  ↔  ( 𝑥  ∈  𝐵  →  𝜒 ) ) ) | 
						
							| 11 |  | albi | ⊢ ( ∀ 𝑥 ( ( 𝑥  ∈  𝐴  →  𝜓 )  ↔  ( 𝑥  ∈  𝐵  →  𝜒 ) )  →  ( ∀ 𝑥 ( 𝑥  ∈  𝐴  →  𝜓 )  ↔  ∀ 𝑥 ( 𝑥  ∈  𝐵  →  𝜒 ) ) ) | 
						
							| 12 | 10 11 | syl | ⊢ ( 𝜑  →  ( ∀ 𝑥 ( 𝑥  ∈  𝐴  →  𝜓 )  ↔  ∀ 𝑥 ( 𝑥  ∈  𝐵  →  𝜒 ) ) ) | 
						
							| 13 |  | df-ral | ⊢ ( ∀ 𝑥  ∈  𝐴 𝜓  ↔  ∀ 𝑥 ( 𝑥  ∈  𝐴  →  𝜓 ) ) | 
						
							| 14 |  | df-ral | ⊢ ( ∀ 𝑥  ∈  𝐵 𝜒  ↔  ∀ 𝑥 ( 𝑥  ∈  𝐵  →  𝜒 ) ) | 
						
							| 15 | 12 13 14 | 3bitr4g | ⊢ ( 𝜑  →  ( ∀ 𝑥  ∈  𝐴 𝜓  ↔  ∀ 𝑥  ∈  𝐵 𝜒 ) ) |