| Step | Hyp | Ref | Expression | 
						
							| 1 |  | prdsmulrngcl.y | ⊢ 𝑌  =  ( 𝑆 Xs 𝑅 ) | 
						
							| 2 |  | prdsmulrngcl.b | ⊢ 𝐵  =  ( Base ‘ 𝑌 ) | 
						
							| 3 |  | prdsmulrngcl.t | ⊢  ·   =  ( .r ‘ 𝑌 ) | 
						
							| 4 |  | prdsmulrngcl.s | ⊢ ( 𝜑  →  𝑆  ∈  𝑉 ) | 
						
							| 5 |  | prdsmulrngcl.i | ⊢ ( 𝜑  →  𝐼  ∈  𝑊 ) | 
						
							| 6 |  | prdsmulrngcl.r | ⊢ ( 𝜑  →  𝑅 : 𝐼 ⟶ Rng ) | 
						
							| 7 |  | prdsmulrngcl.f | ⊢ ( 𝜑  →  𝐹  ∈  𝐵 ) | 
						
							| 8 |  | prdsmulrngcl.g | ⊢ ( 𝜑  →  𝐺  ∈  𝐵 ) | 
						
							| 9 | 6 | ffnd | ⊢ ( 𝜑  →  𝑅  Fn  𝐼 ) | 
						
							| 10 | 1 2 4 5 9 7 8 3 | prdsmulrval | ⊢ ( 𝜑  →  ( 𝐹  ·  𝐺 )  =  ( 𝑥  ∈  𝐼  ↦  ( ( 𝐹 ‘ 𝑥 ) ( .r ‘ ( 𝑅 ‘ 𝑥 ) ) ( 𝐺 ‘ 𝑥 ) ) ) ) | 
						
							| 11 | 6 | ffvelcdmda | ⊢ ( ( 𝜑  ∧  𝑥  ∈  𝐼 )  →  ( 𝑅 ‘ 𝑥 )  ∈  Rng ) | 
						
							| 12 | 4 | adantr | ⊢ ( ( 𝜑  ∧  𝑥  ∈  𝐼 )  →  𝑆  ∈  𝑉 ) | 
						
							| 13 | 5 | adantr | ⊢ ( ( 𝜑  ∧  𝑥  ∈  𝐼 )  →  𝐼  ∈  𝑊 ) | 
						
							| 14 | 9 | adantr | ⊢ ( ( 𝜑  ∧  𝑥  ∈  𝐼 )  →  𝑅  Fn  𝐼 ) | 
						
							| 15 | 7 | adantr | ⊢ ( ( 𝜑  ∧  𝑥  ∈  𝐼 )  →  𝐹  ∈  𝐵 ) | 
						
							| 16 |  | simpr | ⊢ ( ( 𝜑  ∧  𝑥  ∈  𝐼 )  →  𝑥  ∈  𝐼 ) | 
						
							| 17 | 1 2 12 13 14 15 16 | prdsbasprj | ⊢ ( ( 𝜑  ∧  𝑥  ∈  𝐼 )  →  ( 𝐹 ‘ 𝑥 )  ∈  ( Base ‘ ( 𝑅 ‘ 𝑥 ) ) ) | 
						
							| 18 | 8 | adantr | ⊢ ( ( 𝜑  ∧  𝑥  ∈  𝐼 )  →  𝐺  ∈  𝐵 ) | 
						
							| 19 | 1 2 12 13 14 18 16 | prdsbasprj | ⊢ ( ( 𝜑  ∧  𝑥  ∈  𝐼 )  →  ( 𝐺 ‘ 𝑥 )  ∈  ( Base ‘ ( 𝑅 ‘ 𝑥 ) ) ) | 
						
							| 20 |  | eqid | ⊢ ( Base ‘ ( 𝑅 ‘ 𝑥 ) )  =  ( Base ‘ ( 𝑅 ‘ 𝑥 ) ) | 
						
							| 21 |  | eqid | ⊢ ( .r ‘ ( 𝑅 ‘ 𝑥 ) )  =  ( .r ‘ ( 𝑅 ‘ 𝑥 ) ) | 
						
							| 22 | 20 21 | rngcl | ⊢ ( ( ( 𝑅 ‘ 𝑥 )  ∈  Rng  ∧  ( 𝐹 ‘ 𝑥 )  ∈  ( Base ‘ ( 𝑅 ‘ 𝑥 ) )  ∧  ( 𝐺 ‘ 𝑥 )  ∈  ( Base ‘ ( 𝑅 ‘ 𝑥 ) ) )  →  ( ( 𝐹 ‘ 𝑥 ) ( .r ‘ ( 𝑅 ‘ 𝑥 ) ) ( 𝐺 ‘ 𝑥 ) )  ∈  ( Base ‘ ( 𝑅 ‘ 𝑥 ) ) ) | 
						
							| 23 | 11 17 19 22 | syl3anc | ⊢ ( ( 𝜑  ∧  𝑥  ∈  𝐼 )  →  ( ( 𝐹 ‘ 𝑥 ) ( .r ‘ ( 𝑅 ‘ 𝑥 ) ) ( 𝐺 ‘ 𝑥 ) )  ∈  ( Base ‘ ( 𝑅 ‘ 𝑥 ) ) ) | 
						
							| 24 | 23 | ralrimiva | ⊢ ( 𝜑  →  ∀ 𝑥  ∈  𝐼 ( ( 𝐹 ‘ 𝑥 ) ( .r ‘ ( 𝑅 ‘ 𝑥 ) ) ( 𝐺 ‘ 𝑥 ) )  ∈  ( Base ‘ ( 𝑅 ‘ 𝑥 ) ) ) | 
						
							| 25 | 1 2 4 5 9 | prdsbasmpt | ⊢ ( 𝜑  →  ( ( 𝑥  ∈  𝐼  ↦  ( ( 𝐹 ‘ 𝑥 ) ( .r ‘ ( 𝑅 ‘ 𝑥 ) ) ( 𝐺 ‘ 𝑥 ) ) )  ∈  𝐵  ↔  ∀ 𝑥  ∈  𝐼 ( ( 𝐹 ‘ 𝑥 ) ( .r ‘ ( 𝑅 ‘ 𝑥 ) ) ( 𝐺 ‘ 𝑥 ) )  ∈  ( Base ‘ ( 𝑅 ‘ 𝑥 ) ) ) ) | 
						
							| 26 | 24 25 | mpbird | ⊢ ( 𝜑  →  ( 𝑥  ∈  𝐼  ↦  ( ( 𝐹 ‘ 𝑥 ) ( .r ‘ ( 𝑅 ‘ 𝑥 ) ) ( 𝐺 ‘ 𝑥 ) ) )  ∈  𝐵 ) | 
						
							| 27 | 10 26 | eqeltrd | ⊢ ( 𝜑  →  ( 𝐹  ·  𝐺 )  ∈  𝐵 ) |