| Step | Hyp | Ref | Expression | 
						
							| 1 |  | ballotth.m |  |-  M e. NN | 
						
							| 2 |  | ballotth.n |  |-  N e. NN | 
						
							| 3 |  | ballotth.o |  |-  O = { c e. ~P ( 1 ... ( M + N ) ) | ( # ` c ) = M } | 
						
							| 4 |  | ballotth.p |  |-  P = ( x e. ~P O |-> ( ( # ` x ) / ( # ` O ) ) ) | 
						
							| 5 |  | ballotth.f |  |-  F = ( c e. O |-> ( i e. ZZ |-> ( ( # ` ( ( 1 ... i ) i^i c ) ) - ( # ` ( ( 1 ... i ) \ c ) ) ) ) ) | 
						
							| 6 |  | ballotth.e |  |-  E = { c e. O | A. i e. ( 1 ... ( M + N ) ) 0 < ( ( F ` c ) ` i ) } | 
						
							| 7 |  | ballotth.mgtn |  |-  N < M | 
						
							| 8 |  | ballotth.i |  |-  I = ( c e. ( O \ E ) |-> inf ( { k e. ( 1 ... ( M + N ) ) | ( ( F ` c ) ` k ) = 0 } , RR , < ) ) | 
						
							| 9 |  | ballotth.s |  |-  S = ( c e. ( O \ E ) |-> ( i e. ( 1 ... ( M + N ) ) |-> if ( i <_ ( I ` c ) , ( ( ( I ` c ) + 1 ) - i ) , i ) ) ) | 
						
							| 10 |  | simpl |  |-  ( ( d = C /\ i e. ( 1 ... ( M + N ) ) ) -> d = C ) | 
						
							| 11 | 10 | fveq2d |  |-  ( ( d = C /\ i e. ( 1 ... ( M + N ) ) ) -> ( I ` d ) = ( I ` C ) ) | 
						
							| 12 | 11 | breq2d |  |-  ( ( d = C /\ i e. ( 1 ... ( M + N ) ) ) -> ( i <_ ( I ` d ) <-> i <_ ( I ` C ) ) ) | 
						
							| 13 | 11 | oveq1d |  |-  ( ( d = C /\ i e. ( 1 ... ( M + N ) ) ) -> ( ( I ` d ) + 1 ) = ( ( I ` C ) + 1 ) ) | 
						
							| 14 | 13 | oveq1d |  |-  ( ( d = C /\ i e. ( 1 ... ( M + N ) ) ) -> ( ( ( I ` d ) + 1 ) - i ) = ( ( ( I ` C ) + 1 ) - i ) ) | 
						
							| 15 | 12 14 | ifbieq1d |  |-  ( ( d = C /\ i e. ( 1 ... ( M + N ) ) ) -> if ( i <_ ( I ` d ) , ( ( ( I ` d ) + 1 ) - i ) , i ) = if ( i <_ ( I ` C ) , ( ( ( I ` C ) + 1 ) - i ) , i ) ) | 
						
							| 16 | 15 | mpteq2dva |  |-  ( d = C -> ( i e. ( 1 ... ( M + N ) ) |-> if ( i <_ ( I ` d ) , ( ( ( I ` d ) + 1 ) - i ) , i ) ) = ( i e. ( 1 ... ( M + N ) ) |-> if ( i <_ ( I ` C ) , ( ( ( I ` C ) + 1 ) - i ) , i ) ) ) | 
						
							| 17 |  | simpl |  |-  ( ( c = d /\ i e. ( 1 ... ( M + N ) ) ) -> c = d ) | 
						
							| 18 | 17 | fveq2d |  |-  ( ( c = d /\ i e. ( 1 ... ( M + N ) ) ) -> ( I ` c ) = ( I ` d ) ) | 
						
							| 19 | 18 | breq2d |  |-  ( ( c = d /\ i e. ( 1 ... ( M + N ) ) ) -> ( i <_ ( I ` c ) <-> i <_ ( I ` d ) ) ) | 
						
							| 20 | 18 | oveq1d |  |-  ( ( c = d /\ i e. ( 1 ... ( M + N ) ) ) -> ( ( I ` c ) + 1 ) = ( ( I ` d ) + 1 ) ) | 
						
							| 21 | 20 | oveq1d |  |-  ( ( c = d /\ i e. ( 1 ... ( M + N ) ) ) -> ( ( ( I ` c ) + 1 ) - i ) = ( ( ( I ` d ) + 1 ) - i ) ) | 
						
							| 22 | 19 21 | ifbieq1d |  |-  ( ( c = d /\ i e. ( 1 ... ( M + N ) ) ) -> if ( i <_ ( I ` c ) , ( ( ( I ` c ) + 1 ) - i ) , i ) = if ( i <_ ( I ` d ) , ( ( ( I ` d ) + 1 ) - i ) , i ) ) | 
						
							| 23 | 22 | mpteq2dva |  |-  ( c = d -> ( i e. ( 1 ... ( M + N ) ) |-> if ( i <_ ( I ` c ) , ( ( ( I ` c ) + 1 ) - i ) , i ) ) = ( i e. ( 1 ... ( M + N ) ) |-> if ( i <_ ( I ` d ) , ( ( ( I ` d ) + 1 ) - i ) , i ) ) ) | 
						
							| 24 | 23 | cbvmptv |  |-  ( c e. ( O \ E ) |-> ( i e. ( 1 ... ( M + N ) ) |-> if ( i <_ ( I ` c ) , ( ( ( I ` c ) + 1 ) - i ) , i ) ) ) = ( d e. ( O \ E ) |-> ( i e. ( 1 ... ( M + N ) ) |-> if ( i <_ ( I ` d ) , ( ( ( I ` d ) + 1 ) - i ) , i ) ) ) | 
						
							| 25 | 9 24 | eqtri |  |-  S = ( d e. ( O \ E ) |-> ( i e. ( 1 ... ( M + N ) ) |-> if ( i <_ ( I ` d ) , ( ( ( I ` d ) + 1 ) - i ) , i ) ) ) | 
						
							| 26 |  | ovex |  |-  ( 1 ... ( M + N ) ) e. _V | 
						
							| 27 | 26 | mptex |  |-  ( i e. ( 1 ... ( M + N ) ) |-> if ( i <_ ( I ` C ) , ( ( ( I ` C ) + 1 ) - i ) , i ) ) e. _V | 
						
							| 28 | 16 25 27 | fvmpt |  |-  ( C e. ( O \ E ) -> ( S ` C ) = ( i e. ( 1 ... ( M + N ) ) |-> if ( i <_ ( I ` C ) , ( ( ( I ` C ) + 1 ) - i ) , i ) ) ) |