| 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 | 
							
								
							 | 
							ballotth.r | 
							 |-  R = ( c e. ( O \ E ) |-> ( ( S ` c ) " c ) )  | 
						
						
							| 11 | 
							
								
							 | 
							fveq2 | 
							 |-  ( d = C -> ( S ` d ) = ( S ` C ) )  | 
						
						
							| 12 | 
							
								
							 | 
							id | 
							 |-  ( d = C -> d = C )  | 
						
						
							| 13 | 
							
								11 12
							 | 
							imaeq12d | 
							 |-  ( d = C -> ( ( S ` d ) " d ) = ( ( S ` C ) " C ) )  | 
						
						
							| 14 | 
							
								
							 | 
							fveq2 | 
							 |-  ( c = d -> ( S ` c ) = ( S ` d ) )  | 
						
						
							| 15 | 
							
								
							 | 
							id | 
							 |-  ( c = d -> c = d )  | 
						
						
							| 16 | 
							
								14 15
							 | 
							imaeq12d | 
							 |-  ( c = d -> ( ( S ` c ) " c ) = ( ( S ` d ) " d ) )  | 
						
						
							| 17 | 
							
								16
							 | 
							cbvmptv | 
							 |-  ( c e. ( O \ E ) |-> ( ( S ` c ) " c ) ) = ( d e. ( O \ E ) |-> ( ( S ` d ) " d ) )  | 
						
						
							| 18 | 
							
								10 17
							 | 
							eqtri | 
							 |-  R = ( d e. ( O \ E ) |-> ( ( S ` d ) " d ) )  | 
						
						
							| 19 | 
							
								
							 | 
							fvex | 
							 |-  ( S ` C ) e. _V  | 
						
						
							| 20 | 
							
								
							 | 
							imaexg | 
							 |-  ( ( S ` C ) e. _V -> ( ( S ` C ) " C ) e. _V )  | 
						
						
							| 21 | 
							
								19 20
							 | 
							ax-mp | 
							 |-  ( ( S ` C ) " C ) e. _V  | 
						
						
							| 22 | 
							
								13 18 21
							 | 
							fvmpt | 
							 |-  ( C e. ( O \ E ) -> ( R ` C ) = ( ( S ` C ) " C ) )  |