| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							comfffval2.o | 
							 |-  O = ( comf ` C )  | 
						
						
							| 2 | 
							
								
							 | 
							comfffval2.b | 
							 |-  B = ( Base ` C )  | 
						
						
							| 3 | 
							
								
							 | 
							comfffval2.h | 
							 |-  H = ( Homf ` C )  | 
						
						
							| 4 | 
							
								
							 | 
							comfffval2.x | 
							 |-  .x. = ( comp ` C )  | 
						
						
							| 5 | 
							
								
							 | 
							comffval2.x | 
							 |-  ( ph -> X e. B )  | 
						
						
							| 6 | 
							
								
							 | 
							comffval2.y | 
							 |-  ( ph -> Y e. B )  | 
						
						
							| 7 | 
							
								
							 | 
							comffval2.z | 
							 |-  ( ph -> Z e. B )  | 
						
						
							| 8 | 
							
								
							 | 
							comfval2.f | 
							 |-  ( ph -> F e. ( X H Y ) )  | 
						
						
							| 9 | 
							
								
							 | 
							comfval2.g | 
							 |-  ( ph -> G e. ( Y H Z ) )  | 
						
						
							| 10 | 
							
								
							 | 
							eqid | 
							 |-  ( Hom ` C ) = ( Hom ` C )  | 
						
						
							| 11 | 
							
								3 2 10 5 6
							 | 
							homfval | 
							 |-  ( ph -> ( X H Y ) = ( X ( Hom ` C ) Y ) )  | 
						
						
							| 12 | 
							
								8 11
							 | 
							eleqtrd | 
							 |-  ( ph -> F e. ( X ( Hom ` C ) Y ) )  | 
						
						
							| 13 | 
							
								3 2 10 6 7
							 | 
							homfval | 
							 |-  ( ph -> ( Y H Z ) = ( Y ( Hom ` C ) Z ) )  | 
						
						
							| 14 | 
							
								9 13
							 | 
							eleqtrd | 
							 |-  ( ph -> G e. ( Y ( Hom ` C ) Z ) )  | 
						
						
							| 15 | 
							
								1 2 10 4 5 6 7 12 14
							 | 
							comfval | 
							 |-  ( ph -> ( G ( <. X , Y >. O Z ) F ) = ( G ( <. X , Y >. .x. Z ) F ) )  |