| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							srgsummulcr.b | 
							 |-  B = ( Base ` R )  | 
						
						
							| 2 | 
							
								
							 | 
							srgsummulcr.z | 
							 |-  .0. = ( 0g ` R )  | 
						
						
							| 3 | 
							
								
							 | 
							srgsummulcr.p | 
							 |-  .+ = ( +g ` R )  | 
						
						
							| 4 | 
							
								
							 | 
							srgsummulcr.t | 
							 |-  .x. = ( .r ` R )  | 
						
						
							| 5 | 
							
								
							 | 
							srgsummulcr.r | 
							 |-  ( ph -> R e. SRing )  | 
						
						
							| 6 | 
							
								
							 | 
							srgsummulcr.a | 
							 |-  ( ph -> A e. V )  | 
						
						
							| 7 | 
							
								
							 | 
							srgsummulcr.y | 
							 |-  ( ph -> Y e. B )  | 
						
						
							| 8 | 
							
								
							 | 
							srgsummulcr.x | 
							 |-  ( ( ph /\ k e. A ) -> X e. B )  | 
						
						
							| 9 | 
							
								
							 | 
							srgsummulcr.n | 
							 |-  ( ph -> ( k e. A |-> X ) finSupp .0. )  | 
						
						
							| 10 | 
							
								
							 | 
							srgcmn | 
							 |-  ( R e. SRing -> R e. CMnd )  | 
						
						
							| 11 | 
							
								5 10
							 | 
							syl | 
							 |-  ( ph -> R e. CMnd )  | 
						
						
							| 12 | 
							
								
							 | 
							srgmnd | 
							 |-  ( R e. SRing -> R e. Mnd )  | 
						
						
							| 13 | 
							
								5 12
							 | 
							syl | 
							 |-  ( ph -> R e. Mnd )  | 
						
						
							| 14 | 
							
								1 4
							 | 
							srgrmhm | 
							 |-  ( ( R e. SRing /\ Y e. B ) -> ( x e. B |-> ( x .x. Y ) ) e. ( R MndHom R ) )  | 
						
						
							| 15 | 
							
								5 7 14
							 | 
							syl2anc | 
							 |-  ( ph -> ( x e. B |-> ( x .x. Y ) ) e. ( R MndHom R ) )  | 
						
						
							| 16 | 
							
								
							 | 
							oveq1 | 
							 |-  ( x = X -> ( x .x. Y ) = ( X .x. Y ) )  | 
						
						
							| 17 | 
							
								
							 | 
							oveq1 | 
							 |-  ( x = ( R gsum ( k e. A |-> X ) ) -> ( x .x. Y ) = ( ( R gsum ( k e. A |-> X ) ) .x. Y ) )  | 
						
						
							| 18 | 
							
								1 2 11 13 6 15 8 9 16 17
							 | 
							gsummhm2 | 
							 |-  ( ph -> ( R gsum ( k e. A |-> ( X .x. Y ) ) ) = ( ( R gsum ( k e. A |-> X ) ) .x. Y ) )  |