| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							homahom.h | 
							⊢ 𝐻  =  ( Homa ‘ 𝐶 )  | 
						
						
							| 2 | 
							
								
							 | 
							homahom.j | 
							⊢ 𝐽  =  ( Hom  ‘ 𝐶 )  | 
						
						
							| 3 | 
							
								
							 | 
							df-br | 
							⊢ ( 𝑍 ( 𝑋 𝐻 𝑌 ) 𝐹  ↔  〈 𝑍 ,  𝐹 〉  ∈  ( 𝑋 𝐻 𝑌 ) )  | 
						
						
							| 4 | 
							
								
							 | 
							eqid | 
							⊢ ( Base ‘ 𝐶 )  =  ( Base ‘ 𝐶 )  | 
						
						
							| 5 | 
							
								1
							 | 
							homarcl | 
							⊢ ( 〈 𝑍 ,  𝐹 〉  ∈  ( 𝑋 𝐻 𝑌 )  →  𝐶  ∈  Cat )  | 
						
						
							| 6 | 
							
								1 4
							 | 
							homarcl2 | 
							⊢ ( 〈 𝑍 ,  𝐹 〉  ∈  ( 𝑋 𝐻 𝑌 )  →  ( 𝑋  ∈  ( Base ‘ 𝐶 )  ∧  𝑌  ∈  ( Base ‘ 𝐶 ) ) )  | 
						
						
							| 7 | 
							
								6
							 | 
							simpld | 
							⊢ ( 〈 𝑍 ,  𝐹 〉  ∈  ( 𝑋 𝐻 𝑌 )  →  𝑋  ∈  ( Base ‘ 𝐶 ) )  | 
						
						
							| 8 | 
							
								6
							 | 
							simprd | 
							⊢ ( 〈 𝑍 ,  𝐹 〉  ∈  ( 𝑋 𝐻 𝑌 )  →  𝑌  ∈  ( Base ‘ 𝐶 ) )  | 
						
						
							| 9 | 
							
								1 4 5 2 7 8
							 | 
							elhoma | 
							⊢ ( 〈 𝑍 ,  𝐹 〉  ∈  ( 𝑋 𝐻 𝑌 )  →  ( 𝑍 ( 𝑋 𝐻 𝑌 ) 𝐹  ↔  ( 𝑍  =  〈 𝑋 ,  𝑌 〉  ∧  𝐹  ∈  ( 𝑋 𝐽 𝑌 ) ) ) )  | 
						
						
							| 10 | 
							
								3 9
							 | 
							sylbi | 
							⊢ ( 𝑍 ( 𝑋 𝐻 𝑌 ) 𝐹  →  ( 𝑍 ( 𝑋 𝐻 𝑌 ) 𝐹  ↔  ( 𝑍  =  〈 𝑋 ,  𝑌 〉  ∧  𝐹  ∈  ( 𝑋 𝐽 𝑌 ) ) ) )  | 
						
						
							| 11 | 
							
								10
							 | 
							ibi | 
							⊢ ( 𝑍 ( 𝑋 𝐻 𝑌 ) 𝐹  →  ( 𝑍  =  〈 𝑋 ,  𝑌 〉  ∧  𝐹  ∈  ( 𝑋 𝐽 𝑌 ) ) )  | 
						
						
							| 12 | 
							
								11
							 | 
							simprd | 
							⊢ ( 𝑍 ( 𝑋 𝐻 𝑌 ) 𝐹  →  𝐹  ∈  ( 𝑋 𝐽 𝑌 ) )  |