| Step | Hyp | Ref | Expression | 
						
							| 1 |  | imasaddf.f | ⊢ ( 𝜑  →  𝐹 : 𝑉 –onto→ 𝐵 ) | 
						
							| 2 |  | imasaddf.e | ⊢ ( ( 𝜑  ∧  ( 𝑎  ∈  𝑉  ∧  𝑏  ∈  𝑉 )  ∧  ( 𝑝  ∈  𝑉  ∧  𝑞  ∈  𝑉 ) )  →  ( ( ( 𝐹 ‘ 𝑎 )  =  ( 𝐹 ‘ 𝑝 )  ∧  ( 𝐹 ‘ 𝑏 )  =  ( 𝐹 ‘ 𝑞 ) )  →  ( 𝐹 ‘ ( 𝑎  ·  𝑏 ) )  =  ( 𝐹 ‘ ( 𝑝  ·  𝑞 ) ) ) ) | 
						
							| 3 |  | imasaddf.u | ⊢ ( 𝜑  →  𝑈  =  ( 𝐹  “s  𝑅 ) ) | 
						
							| 4 |  | imasaddf.v | ⊢ ( 𝜑  →  𝑉  =  ( Base ‘ 𝑅 ) ) | 
						
							| 5 |  | imasaddf.r | ⊢ ( 𝜑  →  𝑅  ∈  𝑍 ) | 
						
							| 6 |  | imasaddf.p | ⊢  ·   =  ( +g ‘ 𝑅 ) | 
						
							| 7 |  | imasaddf.a | ⊢  ∙   =  ( +g ‘ 𝑈 ) | 
						
							| 8 | 3 4 1 5 6 7 | imasplusg | ⊢ ( 𝜑  →   ∙   =  ∪  𝑝  ∈  𝑉 ∪  𝑞  ∈  𝑉 { 〈 〈 ( 𝐹 ‘ 𝑝 ) ,  ( 𝐹 ‘ 𝑞 ) 〉 ,  ( 𝐹 ‘ ( 𝑝  ·  𝑞 ) ) 〉 } ) | 
						
							| 9 | 1 2 8 | imasaddvallem | ⊢ ( ( 𝜑  ∧  𝑋  ∈  𝑉  ∧  𝑌  ∈  𝑉 )  →  ( ( 𝐹 ‘ 𝑋 )  ∙  ( 𝐹 ‘ 𝑌 ) )  =  ( 𝐹 ‘ ( 𝑋  ·  𝑌 ) ) ) |