| Step | Hyp | Ref | Expression | 
						
							| 1 |  | prdsbasmpt.y | ⊢ 𝑌  =  ( 𝑆 Xs 𝑅 ) | 
						
							| 2 |  | prdsbasmpt.b | ⊢ 𝐵  =  ( Base ‘ 𝑌 ) | 
						
							| 3 |  | prdsbasmpt.s | ⊢ ( 𝜑  →  𝑆  ∈  𝑉 ) | 
						
							| 4 |  | prdsbasmpt.i | ⊢ ( 𝜑  →  𝐼  ∈  𝑊 ) | 
						
							| 5 |  | prdsbasmpt.r | ⊢ ( 𝜑  →  𝑅  Fn  𝐼 ) | 
						
							| 6 | 1 2 3 4 5 | prdsbas2 | ⊢ ( 𝜑  →  𝐵  =  X 𝑥  ∈  𝐼 ( Base ‘ ( 𝑅 ‘ 𝑥 ) ) ) | 
						
							| 7 | 6 | eleq2d | ⊢ ( 𝜑  →  ( ( 𝑥  ∈  𝐼  ↦  𝑈 )  ∈  𝐵  ↔  ( 𝑥  ∈  𝐼  ↦  𝑈 )  ∈  X 𝑥  ∈  𝐼 ( Base ‘ ( 𝑅 ‘ 𝑥 ) ) ) ) | 
						
							| 8 |  | mptelixpg | ⊢ ( 𝐼  ∈  𝑊  →  ( ( 𝑥  ∈  𝐼  ↦  𝑈 )  ∈  X 𝑥  ∈  𝐼 ( Base ‘ ( 𝑅 ‘ 𝑥 ) )  ↔  ∀ 𝑥  ∈  𝐼 𝑈  ∈  ( Base ‘ ( 𝑅 ‘ 𝑥 ) ) ) ) | 
						
							| 9 | 4 8 | syl | ⊢ ( 𝜑  →  ( ( 𝑥  ∈  𝐼  ↦  𝑈 )  ∈  X 𝑥  ∈  𝐼 ( Base ‘ ( 𝑅 ‘ 𝑥 ) )  ↔  ∀ 𝑥  ∈  𝐼 𝑈  ∈  ( Base ‘ ( 𝑅 ‘ 𝑥 ) ) ) ) | 
						
							| 10 | 7 9 | bitrd | ⊢ ( 𝜑  →  ( ( 𝑥  ∈  𝐼  ↦  𝑈 )  ∈  𝐵  ↔  ∀ 𝑥  ∈  𝐼 𝑈  ∈  ( Base ‘ ( 𝑅 ‘ 𝑥 ) ) ) ) |