| Step | Hyp | Ref | Expression | 
						
							| 1 |  | cpm2mfval.i |  |-  I = ( N cPolyMatToMat R ) | 
						
							| 2 |  | cpm2mfval.s |  |-  S = ( N ConstPolyMat R ) | 
						
							| 3 |  | df-cpmat2mat |  |-  cPolyMatToMat = ( n e. Fin , r e. _V |-> ( m e. ( n ConstPolyMat r ) |-> ( x e. n , y e. n |-> ( ( coe1 ` ( x m y ) ) ` 0 ) ) ) ) | 
						
							| 4 | 3 | a1i |  |-  ( ( N e. Fin /\ R e. V ) -> cPolyMatToMat = ( n e. Fin , r e. _V |-> ( m e. ( n ConstPolyMat r ) |-> ( x e. n , y e. n |-> ( ( coe1 ` ( x m y ) ) ` 0 ) ) ) ) ) | 
						
							| 5 |  | oveq12 |  |-  ( ( n = N /\ r = R ) -> ( n ConstPolyMat r ) = ( N ConstPolyMat R ) ) | 
						
							| 6 | 5 2 | eqtr4di |  |-  ( ( n = N /\ r = R ) -> ( n ConstPolyMat r ) = S ) | 
						
							| 7 |  | simpl |  |-  ( ( n = N /\ r = R ) -> n = N ) | 
						
							| 8 |  | eqidd |  |-  ( ( n = N /\ r = R ) -> ( ( coe1 ` ( x m y ) ) ` 0 ) = ( ( coe1 ` ( x m y ) ) ` 0 ) ) | 
						
							| 9 | 7 7 8 | mpoeq123dv |  |-  ( ( n = N /\ r = R ) -> ( x e. n , y e. n |-> ( ( coe1 ` ( x m y ) ) ` 0 ) ) = ( x e. N , y e. N |-> ( ( coe1 ` ( x m y ) ) ` 0 ) ) ) | 
						
							| 10 | 6 9 | mpteq12dv |  |-  ( ( n = N /\ r = R ) -> ( m e. ( n ConstPolyMat r ) |-> ( x e. n , y e. n |-> ( ( coe1 ` ( x m y ) ) ` 0 ) ) ) = ( m e. S |-> ( x e. N , y e. N |-> ( ( coe1 ` ( x m y ) ) ` 0 ) ) ) ) | 
						
							| 11 | 10 | adantl |  |-  ( ( ( N e. Fin /\ R e. V ) /\ ( n = N /\ r = R ) ) -> ( m e. ( n ConstPolyMat r ) |-> ( x e. n , y e. n |-> ( ( coe1 ` ( x m y ) ) ` 0 ) ) ) = ( m e. S |-> ( x e. N , y e. N |-> ( ( coe1 ` ( x m y ) ) ` 0 ) ) ) ) | 
						
							| 12 |  | simpl |  |-  ( ( N e. Fin /\ R e. V ) -> N e. Fin ) | 
						
							| 13 |  | elex |  |-  ( R e. V -> R e. _V ) | 
						
							| 14 | 13 | adantl |  |-  ( ( N e. Fin /\ R e. V ) -> R e. _V ) | 
						
							| 15 | 2 | ovexi |  |-  S e. _V | 
						
							| 16 |  | mptexg |  |-  ( S e. _V -> ( m e. S |-> ( x e. N , y e. N |-> ( ( coe1 ` ( x m y ) ) ` 0 ) ) ) e. _V ) | 
						
							| 17 | 15 16 | mp1i |  |-  ( ( N e. Fin /\ R e. V ) -> ( m e. S |-> ( x e. N , y e. N |-> ( ( coe1 ` ( x m y ) ) ` 0 ) ) ) e. _V ) | 
						
							| 18 | 4 11 12 14 17 | ovmpod |  |-  ( ( N e. Fin /\ R e. V ) -> ( N cPolyMatToMat R ) = ( m e. S |-> ( x e. N , y e. N |-> ( ( coe1 ` ( x m y ) ) ` 0 ) ) ) ) | 
						
							| 19 | 1 18 | eqtrid |  |-  ( ( N e. Fin /\ R e. V ) -> I = ( m e. S |-> ( x e. N , y e. N |-> ( ( coe1 ` ( x m y ) ) ` 0 ) ) ) ) |