| 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 |  | prdsplusgval.f | ⊢ ( 𝜑  →  𝐹  ∈  𝐵 ) | 
						
							| 7 |  | prdsplusgval.g | ⊢ ( 𝜑  →  𝐺  ∈  𝐵 ) | 
						
							| 8 |  | prdsplusgval.p | ⊢  +   =  ( +g ‘ 𝑌 ) | 
						
							| 9 |  | fnex | ⊢ ( ( 𝑅  Fn  𝐼  ∧  𝐼  ∈  𝑊 )  →  𝑅  ∈  V ) | 
						
							| 10 | 5 4 9 | syl2anc | ⊢ ( 𝜑  →  𝑅  ∈  V ) | 
						
							| 11 | 5 | fndmd | ⊢ ( 𝜑  →  dom  𝑅  =  𝐼 ) | 
						
							| 12 | 1 3 10 2 11 8 | prdsplusg | ⊢ ( 𝜑  →   +   =  ( 𝑦  ∈  𝐵 ,  𝑧  ∈  𝐵  ↦  ( 𝑥  ∈  𝐼  ↦  ( ( 𝑦 ‘ 𝑥 ) ( +g ‘ ( 𝑅 ‘ 𝑥 ) ) ( 𝑧 ‘ 𝑥 ) ) ) ) ) | 
						
							| 13 |  | fveq1 | ⊢ ( 𝑦  =  𝐹  →  ( 𝑦 ‘ 𝑥 )  =  ( 𝐹 ‘ 𝑥 ) ) | 
						
							| 14 |  | fveq1 | ⊢ ( 𝑧  =  𝐺  →  ( 𝑧 ‘ 𝑥 )  =  ( 𝐺 ‘ 𝑥 ) ) | 
						
							| 15 | 13 14 | oveqan12d | ⊢ ( ( 𝑦  =  𝐹  ∧  𝑧  =  𝐺 )  →  ( ( 𝑦 ‘ 𝑥 ) ( +g ‘ ( 𝑅 ‘ 𝑥 ) ) ( 𝑧 ‘ 𝑥 ) )  =  ( ( 𝐹 ‘ 𝑥 ) ( +g ‘ ( 𝑅 ‘ 𝑥 ) ) ( 𝐺 ‘ 𝑥 ) ) ) | 
						
							| 16 | 15 | adantl | ⊢ ( ( 𝜑  ∧  ( 𝑦  =  𝐹  ∧  𝑧  =  𝐺 ) )  →  ( ( 𝑦 ‘ 𝑥 ) ( +g ‘ ( 𝑅 ‘ 𝑥 ) ) ( 𝑧 ‘ 𝑥 ) )  =  ( ( 𝐹 ‘ 𝑥 ) ( +g ‘ ( 𝑅 ‘ 𝑥 ) ) ( 𝐺 ‘ 𝑥 ) ) ) | 
						
							| 17 | 16 | mpteq2dv | ⊢ ( ( 𝜑  ∧  ( 𝑦  =  𝐹  ∧  𝑧  =  𝐺 ) )  →  ( 𝑥  ∈  𝐼  ↦  ( ( 𝑦 ‘ 𝑥 ) ( +g ‘ ( 𝑅 ‘ 𝑥 ) ) ( 𝑧 ‘ 𝑥 ) ) )  =  ( 𝑥  ∈  𝐼  ↦  ( ( 𝐹 ‘ 𝑥 ) ( +g ‘ ( 𝑅 ‘ 𝑥 ) ) ( 𝐺 ‘ 𝑥 ) ) ) ) | 
						
							| 18 | 4 | mptexd | ⊢ ( 𝜑  →  ( 𝑥  ∈  𝐼  ↦  ( ( 𝐹 ‘ 𝑥 ) ( +g ‘ ( 𝑅 ‘ 𝑥 ) ) ( 𝐺 ‘ 𝑥 ) ) )  ∈  V ) | 
						
							| 19 | 12 17 6 7 18 | ovmpod | ⊢ ( 𝜑  →  ( 𝐹  +  𝐺 )  =  ( 𝑥  ∈  𝐼  ↦  ( ( 𝐹 ‘ 𝑥 ) ( +g ‘ ( 𝑅 ‘ 𝑥 ) ) ( 𝐺 ‘ 𝑥 ) ) ) ) |