| Step | 
						Hyp | 
						Ref | 
						Expression | 
					
						
							| 1 | 
							
								
							 | 
							setcval.c | 
							 |-  C = ( SetCat ` U )  | 
						
						
							| 2 | 
							
								
							 | 
							setcval.u | 
							 |-  ( ph -> U e. V )  | 
						
						
							| 3 | 
							
								
							 | 
							setcval.h | 
							 |-  ( ph -> H = ( x e. U , y e. U |-> ( y ^m x ) ) )  | 
						
						
							| 4 | 
							
								
							 | 
							setcval.o | 
							 |-  ( ph -> .x. = ( v e. ( U X. U ) , z e. U |-> ( g e. ( z ^m ( 2nd ` v ) ) , f e. ( ( 2nd ` v ) ^m ( 1st ` v ) ) |-> ( g o. f ) ) ) )  | 
						
						
							| 5 | 
							
								
							 | 
							df-setc | 
							 |-  SetCat = ( u e. _V |-> { <. ( Base ` ndx ) , u >. , <. ( Hom ` ndx ) , ( x e. u , y e. u |-> ( y ^m x ) ) >. , <. ( comp ` ndx ) , ( v e. ( u X. u ) , z e. u |-> ( g e. ( z ^m ( 2nd ` v ) ) , f e. ( ( 2nd ` v ) ^m ( 1st ` v ) ) |-> ( g o. f ) ) ) >. } ) | 
						
						
							| 6 | 
							
								
							 | 
							simpr | 
							 |-  ( ( ph /\ u = U ) -> u = U )  | 
						
						
							| 7 | 
							
								6
							 | 
							opeq2d | 
							 |-  ( ( ph /\ u = U ) -> <. ( Base ` ndx ) , u >. = <. ( Base ` ndx ) , U >. )  | 
						
						
							| 8 | 
							
								
							 | 
							eqidd | 
							 |-  ( ( ph /\ u = U ) -> ( y ^m x ) = ( y ^m x ) )  | 
						
						
							| 9 | 
							
								6 6 8
							 | 
							mpoeq123dv | 
							 |-  ( ( ph /\ u = U ) -> ( x e. u , y e. u |-> ( y ^m x ) ) = ( x e. U , y e. U |-> ( y ^m x ) ) )  | 
						
						
							| 10 | 
							
								3
							 | 
							adantr | 
							 |-  ( ( ph /\ u = U ) -> H = ( x e. U , y e. U |-> ( y ^m x ) ) )  | 
						
						
							| 11 | 
							
								9 10
							 | 
							eqtr4d | 
							 |-  ( ( ph /\ u = U ) -> ( x e. u , y e. u |-> ( y ^m x ) ) = H )  | 
						
						
							| 12 | 
							
								11
							 | 
							opeq2d | 
							 |-  ( ( ph /\ u = U ) -> <. ( Hom ` ndx ) , ( x e. u , y e. u |-> ( y ^m x ) ) >. = <. ( Hom ` ndx ) , H >. )  | 
						
						
							| 13 | 
							
								6
							 | 
							sqxpeqd | 
							 |-  ( ( ph /\ u = U ) -> ( u X. u ) = ( U X. U ) )  | 
						
						
							| 14 | 
							
								
							 | 
							eqidd | 
							 |-  ( ( ph /\ u = U ) -> ( g e. ( z ^m ( 2nd ` v ) ) , f e. ( ( 2nd ` v ) ^m ( 1st ` v ) ) |-> ( g o. f ) ) = ( g e. ( z ^m ( 2nd ` v ) ) , f e. ( ( 2nd ` v ) ^m ( 1st ` v ) ) |-> ( g o. f ) ) )  | 
						
						
							| 15 | 
							
								13 6 14
							 | 
							mpoeq123dv | 
							 |-  ( ( ph /\ u = U ) -> ( v e. ( u X. u ) , z e. u |-> ( g e. ( z ^m ( 2nd ` v ) ) , f e. ( ( 2nd ` v ) ^m ( 1st ` v ) ) |-> ( g o. f ) ) ) = ( v e. ( U X. U ) , z e. U |-> ( g e. ( z ^m ( 2nd ` v ) ) , f e. ( ( 2nd ` v ) ^m ( 1st ` v ) ) |-> ( g o. f ) ) ) )  | 
						
						
							| 16 | 
							
								4
							 | 
							adantr | 
							 |-  ( ( ph /\ u = U ) -> .x. = ( v e. ( U X. U ) , z e. U |-> ( g e. ( z ^m ( 2nd ` v ) ) , f e. ( ( 2nd ` v ) ^m ( 1st ` v ) ) |-> ( g o. f ) ) ) )  | 
						
						
							| 17 | 
							
								15 16
							 | 
							eqtr4d | 
							 |-  ( ( ph /\ u = U ) -> ( v e. ( u X. u ) , z e. u |-> ( g e. ( z ^m ( 2nd ` v ) ) , f e. ( ( 2nd ` v ) ^m ( 1st ` v ) ) |-> ( g o. f ) ) ) = .x. )  | 
						
						
							| 18 | 
							
								17
							 | 
							opeq2d | 
							 |-  ( ( ph /\ u = U ) -> <. ( comp ` ndx ) , ( v e. ( u X. u ) , z e. u |-> ( g e. ( z ^m ( 2nd ` v ) ) , f e. ( ( 2nd ` v ) ^m ( 1st ` v ) ) |-> ( g o. f ) ) ) >. = <. ( comp ` ndx ) , .x. >. )  | 
						
						
							| 19 | 
							
								7 12 18
							 | 
							tpeq123d | 
							 |-  ( ( ph /\ u = U ) -> { <. ( Base ` ndx ) , u >. , <. ( Hom ` ndx ) , ( x e. u , y e. u |-> ( y ^m x ) ) >. , <. ( comp ` ndx ) , ( v e. ( u X. u ) , z e. u |-> ( g e. ( z ^m ( 2nd ` v ) ) , f e. ( ( 2nd ` v ) ^m ( 1st ` v ) ) |-> ( g o. f ) ) ) >. } = { <. ( Base ` ndx ) , U >. , <. ( Hom ` ndx ) , H >. , <. ( comp ` ndx ) , .x. >. } ) | 
						
						
							| 20 | 
							
								2
							 | 
							elexd | 
							 |-  ( ph -> U e. _V )  | 
						
						
							| 21 | 
							
								
							 | 
							tpex | 
							 |-  { <. ( Base ` ndx ) , U >. , <. ( Hom ` ndx ) , H >. , <. ( comp ` ndx ) , .x. >. } e. _V | 
						
						
							| 22 | 
							
								21
							 | 
							a1i | 
							 |-  ( ph -> { <. ( Base ` ndx ) , U >. , <. ( Hom ` ndx ) , H >. , <. ( comp ` ndx ) , .x. >. } e. _V ) | 
						
						
							| 23 | 
							
								5 19 20 22
							 | 
							fvmptd2 | 
							 |-  ( ph -> ( SetCat ` U ) = { <. ( Base ` ndx ) , U >. , <. ( Hom ` ndx ) , H >. , <. ( comp ` ndx ) , .x. >. } ) | 
						
						
							| 24 | 
							
								1 23
							 | 
							eqtrid | 
							 |-  ( ph -> C = { <. ( Base ` ndx ) , U >. , <. ( Hom ` ndx ) , H >. , <. ( comp ` ndx ) , .x. >. } ) |