| Step | Hyp | Ref | Expression | 
						
							| 1 |  | fvex |  |-  ( # ` dom c ) e. _V | 
						
							| 2 |  | oveq2 |  |-  ( n = ( # ` dom c ) -> ( X ^ n ) = ( X ^ ( # ` dom c ) ) ) | 
						
							| 3 |  | oveq1 |  |-  ( n = ( # ` dom c ) -> ( n _C m ) = ( ( # ` dom c ) _C m ) ) | 
						
							| 4 |  | oveq1 |  |-  ( n = ( # ` dom c ) -> ( n - m ) = ( ( # ` dom c ) - m ) ) | 
						
							| 5 | 4 | oveq1d |  |-  ( n = ( # ` dom c ) -> ( ( n - m ) + 1 ) = ( ( ( # ` dom c ) - m ) + 1 ) ) | 
						
							| 6 | 5 | oveq2d |  |-  ( n = ( # ` dom c ) -> ( ( c ` m ) / ( ( n - m ) + 1 ) ) = ( ( c ` m ) / ( ( ( # ` dom c ) - m ) + 1 ) ) ) | 
						
							| 7 | 3 6 | oveq12d |  |-  ( n = ( # ` dom c ) -> ( ( n _C m ) x. ( ( c ` m ) / ( ( n - m ) + 1 ) ) ) = ( ( ( # ` dom c ) _C m ) x. ( ( c ` m ) / ( ( ( # ` dom c ) - m ) + 1 ) ) ) ) | 
						
							| 8 | 7 | sumeq2sdv |  |-  ( n = ( # ` dom c ) -> sum_ m e. dom c ( ( n _C m ) x. ( ( c ` m ) / ( ( n - m ) + 1 ) ) ) = sum_ m e. dom c ( ( ( # ` dom c ) _C m ) x. ( ( c ` m ) / ( ( ( # ` dom c ) - m ) + 1 ) ) ) ) | 
						
							| 9 | 2 8 | oveq12d |  |-  ( n = ( # ` dom c ) -> ( ( X ^ n ) - sum_ m e. dom c ( ( n _C m ) x. ( ( c ` m ) / ( ( n - m ) + 1 ) ) ) ) = ( ( X ^ ( # ` dom c ) ) - sum_ m e. dom c ( ( ( # ` dom c ) _C m ) x. ( ( c ` m ) / ( ( ( # ` dom c ) - m ) + 1 ) ) ) ) ) | 
						
							| 10 | 1 9 | csbie |  |-  [_ ( # ` dom c ) / n ]_ ( ( X ^ n ) - sum_ m e. dom c ( ( n _C m ) x. ( ( c ` m ) / ( ( n - m ) + 1 ) ) ) ) = ( ( X ^ ( # ` dom c ) ) - sum_ m e. dom c ( ( ( # ` dom c ) _C m ) x. ( ( c ` m ) / ( ( ( # ` dom c ) - m ) + 1 ) ) ) ) | 
						
							| 11 |  | oveq2 |  |-  ( m = k -> ( n _C m ) = ( n _C k ) ) | 
						
							| 12 |  | fveq2 |  |-  ( m = k -> ( c ` m ) = ( c ` k ) ) | 
						
							| 13 |  | oveq2 |  |-  ( m = k -> ( n - m ) = ( n - k ) ) | 
						
							| 14 | 13 | oveq1d |  |-  ( m = k -> ( ( n - m ) + 1 ) = ( ( n - k ) + 1 ) ) | 
						
							| 15 | 12 14 | oveq12d |  |-  ( m = k -> ( ( c ` m ) / ( ( n - m ) + 1 ) ) = ( ( c ` k ) / ( ( n - k ) + 1 ) ) ) | 
						
							| 16 | 11 15 | oveq12d |  |-  ( m = k -> ( ( n _C m ) x. ( ( c ` m ) / ( ( n - m ) + 1 ) ) ) = ( ( n _C k ) x. ( ( c ` k ) / ( ( n - k ) + 1 ) ) ) ) | 
						
							| 17 | 16 | cbvsumv |  |-  sum_ m e. dom c ( ( n _C m ) x. ( ( c ` m ) / ( ( n - m ) + 1 ) ) ) = sum_ k e. dom c ( ( n _C k ) x. ( ( c ` k ) / ( ( n - k ) + 1 ) ) ) | 
						
							| 18 |  | dmeq |  |-  ( c = g -> dom c = dom g ) | 
						
							| 19 |  | fveq1 |  |-  ( c = g -> ( c ` k ) = ( g ` k ) ) | 
						
							| 20 | 19 | oveq1d |  |-  ( c = g -> ( ( c ` k ) / ( ( n - k ) + 1 ) ) = ( ( g ` k ) / ( ( n - k ) + 1 ) ) ) | 
						
							| 21 | 20 | oveq2d |  |-  ( c = g -> ( ( n _C k ) x. ( ( c ` k ) / ( ( n - k ) + 1 ) ) ) = ( ( n _C k ) x. ( ( g ` k ) / ( ( n - k ) + 1 ) ) ) ) | 
						
							| 22 | 21 | adantr |  |-  ( ( c = g /\ k e. dom c ) -> ( ( n _C k ) x. ( ( c ` k ) / ( ( n - k ) + 1 ) ) ) = ( ( n _C k ) x. ( ( g ` k ) / ( ( n - k ) + 1 ) ) ) ) | 
						
							| 23 | 18 22 | sumeq12dv |  |-  ( c = g -> sum_ k e. dom c ( ( n _C k ) x. ( ( c ` k ) / ( ( n - k ) + 1 ) ) ) = sum_ k e. dom g ( ( n _C k ) x. ( ( g ` k ) / ( ( n - k ) + 1 ) ) ) ) | 
						
							| 24 | 17 23 | eqtrid |  |-  ( c = g -> sum_ m e. dom c ( ( n _C m ) x. ( ( c ` m ) / ( ( n - m ) + 1 ) ) ) = sum_ k e. dom g ( ( n _C k ) x. ( ( g ` k ) / ( ( n - k ) + 1 ) ) ) ) | 
						
							| 25 | 24 | oveq2d |  |-  ( c = g -> ( ( X ^ n ) - sum_ m e. dom c ( ( n _C m ) x. ( ( c ` m ) / ( ( n - m ) + 1 ) ) ) ) = ( ( X ^ n ) - sum_ k e. dom g ( ( n _C k ) x. ( ( g ` k ) / ( ( n - k ) + 1 ) ) ) ) ) | 
						
							| 26 | 25 | csbeq2dv |  |-  ( c = g -> [_ ( # ` dom c ) / n ]_ ( ( X ^ n ) - sum_ m e. dom c ( ( n _C m ) x. ( ( c ` m ) / ( ( n - m ) + 1 ) ) ) ) = [_ ( # ` dom c ) / n ]_ ( ( X ^ n ) - sum_ k e. dom g ( ( n _C k ) x. ( ( g ` k ) / ( ( n - k ) + 1 ) ) ) ) ) | 
						
							| 27 | 10 26 | eqtr3id |  |-  ( c = g -> ( ( X ^ ( # ` dom c ) ) - sum_ m e. dom c ( ( ( # ` dom c ) _C m ) x. ( ( c ` m ) / ( ( ( # ` dom c ) - m ) + 1 ) ) ) ) = [_ ( # ` dom c ) / n ]_ ( ( X ^ n ) - sum_ k e. dom g ( ( n _C k ) x. ( ( g ` k ) / ( ( n - k ) + 1 ) ) ) ) ) | 
						
							| 28 | 18 | fveq2d |  |-  ( c = g -> ( # ` dom c ) = ( # ` dom g ) ) | 
						
							| 29 | 28 | csbeq1d |  |-  ( c = g -> [_ ( # ` dom c ) / n ]_ ( ( X ^ n ) - sum_ k e. dom g ( ( n _C k ) x. ( ( g ` k ) / ( ( n - k ) + 1 ) ) ) ) = [_ ( # ` dom g ) / n ]_ ( ( X ^ n ) - sum_ k e. dom g ( ( n _C k ) x. ( ( g ` k ) / ( ( n - k ) + 1 ) ) ) ) ) | 
						
							| 30 | 27 29 | eqtrd |  |-  ( c = g -> ( ( X ^ ( # ` dom c ) ) - sum_ m e. dom c ( ( ( # ` dom c ) _C m ) x. ( ( c ` m ) / ( ( ( # ` dom c ) - m ) + 1 ) ) ) ) = [_ ( # ` dom g ) / n ]_ ( ( X ^ n ) - sum_ k e. dom g ( ( n _C k ) x. ( ( g ` k ) / ( ( n - k ) + 1 ) ) ) ) ) | 
						
							| 31 | 30 | cbvmptv |  |-  ( c e. _V |-> ( ( X ^ ( # ` dom c ) ) - sum_ m e. dom c ( ( ( # ` dom c ) _C m ) x. ( ( c ` m ) / ( ( ( # ` dom c ) - m ) + 1 ) ) ) ) ) = ( g e. _V |-> [_ ( # ` dom g ) / n ]_ ( ( X ^ n ) - sum_ k e. dom g ( ( n _C k ) x. ( ( g ` k ) / ( ( n - k ) + 1 ) ) ) ) ) | 
						
							| 32 |  | eqid |  |-  wrecs ( < , NN0 , ( c e. _V |-> ( ( X ^ ( # ` dom c ) ) - sum_ m e. dom c ( ( ( # ` dom c ) _C m ) x. ( ( c ` m ) / ( ( ( # ` dom c ) - m ) + 1 ) ) ) ) ) ) = wrecs ( < , NN0 , ( c e. _V |-> ( ( X ^ ( # ` dom c ) ) - sum_ m e. dom c ( ( ( # ` dom c ) _C m ) x. ( ( c ` m ) / ( ( ( # ` dom c ) - m ) + 1 ) ) ) ) ) ) | 
						
							| 33 | 31 32 | bpolylem |  |-  ( ( N e. NN0 /\ X e. CC ) -> ( N BernPoly X ) = ( ( X ^ N ) - sum_ k e. ( 0 ... ( N - 1 ) ) ( ( N _C k ) x. ( ( k BernPoly X ) / ( ( N - k ) + 1 ) ) ) ) ) |