| 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 ) ) |