| Step | Hyp | Ref | Expression | 
						
							| 1 |  | rngchomffvalALTV.c |  |-  C = ( RngCatALTV ` U ) | 
						
							| 2 |  | rngchomffvalALTV.b |  |-  B = ( Base ` C ) | 
						
							| 3 |  | rngchomffvalALTV.u |  |-  ( ph -> U e. V ) | 
						
							| 4 |  | rngchomffvalALTV.h |  |-  F = ( Homf ` C ) | 
						
							| 5 |  | eqid |  |-  ( Hom ` C ) = ( Hom ` C ) | 
						
							| 6 | 1 2 3 5 | rngchomfvalALTV |  |-  ( ph -> ( Hom ` C ) = ( x e. B , y e. B |-> ( x RngHom y ) ) ) | 
						
							| 7 |  | eqid |  |-  ( x e. B , y e. B |-> ( x RngHom y ) ) = ( x e. B , y e. B |-> ( x RngHom y ) ) | 
						
							| 8 |  | ovex |  |-  ( x RngHom y ) e. _V | 
						
							| 9 | 7 8 | fnmpoi |  |-  ( x e. B , y e. B |-> ( x RngHom y ) ) Fn ( B X. B ) | 
						
							| 10 |  | fneq1 |  |-  ( ( Hom ` C ) = ( x e. B , y e. B |-> ( x RngHom y ) ) -> ( ( Hom ` C ) Fn ( B X. B ) <-> ( x e. B , y e. B |-> ( x RngHom y ) ) Fn ( B X. B ) ) ) | 
						
							| 11 | 9 10 | mpbiri |  |-  ( ( Hom ` C ) = ( x e. B , y e. B |-> ( x RngHom y ) ) -> ( Hom ` C ) Fn ( B X. B ) ) | 
						
							| 12 | 4 2 5 | fnhomeqhomf |  |-  ( ( Hom ` C ) Fn ( B X. B ) -> F = ( Hom ` C ) ) | 
						
							| 13 | 6 11 12 | 3syl |  |-  ( ph -> F = ( Hom ` C ) ) | 
						
							| 14 | 13 6 | eqtrd |  |-  ( ph -> F = ( x e. B , y e. B |-> ( x RngHom y ) ) ) |