| Step | Hyp | Ref | Expression | 
						
							| 1 |  | rngchomffvalALTV.c | ⊢ 𝐶  =  ( RngCatALTV ‘ 𝑈 ) | 
						
							| 2 |  | rngchomffvalALTV.b | ⊢ 𝐵  =  ( Base ‘ 𝐶 ) | 
						
							| 3 |  | rngchomffvalALTV.u | ⊢ ( 𝜑  →  𝑈  ∈  𝑉 ) | 
						
							| 4 |  | rngchomffvalALTV.h | ⊢ 𝐹  =  ( Homf  ‘ 𝐶 ) | 
						
							| 5 |  | eqid | ⊢ ( Hom  ‘ 𝐶 )  =  ( Hom  ‘ 𝐶 ) | 
						
							| 6 | 1 2 3 5 | rngchomfvalALTV | ⊢ ( 𝜑  →  ( Hom  ‘ 𝐶 )  =  ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐵  ↦  ( 𝑥  RngHom  𝑦 ) ) ) | 
						
							| 7 |  | eqid | ⊢ ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐵  ↦  ( 𝑥  RngHom  𝑦 ) )  =  ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐵  ↦  ( 𝑥  RngHom  𝑦 ) ) | 
						
							| 8 |  | ovex | ⊢ ( 𝑥  RngHom  𝑦 )  ∈  V | 
						
							| 9 | 7 8 | fnmpoi | ⊢ ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐵  ↦  ( 𝑥  RngHom  𝑦 ) )  Fn  ( 𝐵  ×  𝐵 ) | 
						
							| 10 |  | fneq1 | ⊢ ( ( Hom  ‘ 𝐶 )  =  ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐵  ↦  ( 𝑥  RngHom  𝑦 ) )  →  ( ( Hom  ‘ 𝐶 )  Fn  ( 𝐵  ×  𝐵 )  ↔  ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐵  ↦  ( 𝑥  RngHom  𝑦 ) )  Fn  ( 𝐵  ×  𝐵 ) ) ) | 
						
							| 11 | 9 10 | mpbiri | ⊢ ( ( Hom  ‘ 𝐶 )  =  ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐵  ↦  ( 𝑥  RngHom  𝑦 ) )  →  ( Hom  ‘ 𝐶 )  Fn  ( 𝐵  ×  𝐵 ) ) | 
						
							| 12 | 4 2 5 | fnhomeqhomf | ⊢ ( ( Hom  ‘ 𝐶 )  Fn  ( 𝐵  ×  𝐵 )  →  𝐹  =  ( Hom  ‘ 𝐶 ) ) | 
						
							| 13 | 6 11 12 | 3syl | ⊢ ( 𝜑  →  𝐹  =  ( Hom  ‘ 𝐶 ) ) | 
						
							| 14 | 13 6 | eqtrd | ⊢ ( 𝜑  →  𝐹  =  ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐵  ↦  ( 𝑥  RngHom  𝑦 ) ) ) |