| Step | Hyp | Ref | Expression | 
						
							| 1 |  | mdetfval1.d |  |-  D = ( N maDet R ) | 
						
							| 2 |  | mdetfval1.a |  |-  A = ( N Mat R ) | 
						
							| 3 |  | mdetfval1.b |  |-  B = ( Base ` A ) | 
						
							| 4 |  | mdetfval1.p |  |-  P = ( Base ` ( SymGrp ` N ) ) | 
						
							| 5 |  | mdetfval1.y |  |-  Y = ( ZRHom ` R ) | 
						
							| 6 |  | mdetfval1.s |  |-  S = ( pmSgn ` N ) | 
						
							| 7 |  | mdetfval1.t |  |-  .x. = ( .r ` R ) | 
						
							| 8 |  | mdetfval1.u |  |-  U = ( mulGrp ` R ) | 
						
							| 9 |  | oveq |  |-  ( m = M -> ( ( p ` x ) m x ) = ( ( p ` x ) M x ) ) | 
						
							| 10 | 9 | mpteq2dv |  |-  ( m = M -> ( x e. N |-> ( ( p ` x ) m x ) ) = ( x e. N |-> ( ( p ` x ) M x ) ) ) | 
						
							| 11 | 10 | oveq2d |  |-  ( m = M -> ( U gsum ( x e. N |-> ( ( p ` x ) m x ) ) ) = ( U gsum ( x e. N |-> ( ( p ` x ) M x ) ) ) ) | 
						
							| 12 | 11 | oveq2d |  |-  ( m = M -> ( ( Y ` ( S ` p ) ) .x. ( U gsum ( x e. N |-> ( ( p ` x ) m x ) ) ) ) = ( ( Y ` ( S ` p ) ) .x. ( U gsum ( x e. N |-> ( ( p ` x ) M x ) ) ) ) ) | 
						
							| 13 | 12 | mpteq2dv |  |-  ( m = M -> ( p e. P |-> ( ( Y ` ( S ` p ) ) .x. ( U gsum ( x e. N |-> ( ( p ` x ) m x ) ) ) ) ) = ( p e. P |-> ( ( Y ` ( S ` p ) ) .x. ( U gsum ( x e. N |-> ( ( p ` x ) M x ) ) ) ) ) ) | 
						
							| 14 | 13 | oveq2d |  |-  ( m = M -> ( R gsum ( p e. P |-> ( ( Y ` ( S ` p ) ) .x. ( U gsum ( x e. N |-> ( ( p ` x ) m x ) ) ) ) ) ) = ( R gsum ( p e. P |-> ( ( Y ` ( S ` p ) ) .x. ( U gsum ( x e. N |-> ( ( p ` x ) M x ) ) ) ) ) ) ) | 
						
							| 15 | 1 2 3 4 5 6 7 8 | mdetfval1 |  |-  D = ( m e. B |-> ( R gsum ( p e. P |-> ( ( Y ` ( S ` p ) ) .x. ( U gsum ( x e. N |-> ( ( p ` x ) m x ) ) ) ) ) ) ) | 
						
							| 16 |  | ovex |  |-  ( R gsum ( p e. P |-> ( ( Y ` ( S ` p ) ) .x. ( U gsum ( x e. N |-> ( ( p ` x ) M x ) ) ) ) ) ) e. _V | 
						
							| 17 | 14 15 16 | fvmpt |  |-  ( M e. B -> ( D ` M ) = ( R gsum ( p e. P |-> ( ( Y ` ( S ` p ) ) .x. ( U gsum ( x e. N |-> ( ( p ` x ) M x ) ) ) ) ) ) ) |