| Step | Hyp | Ref | Expression | 
						
							| 1 |  | ballotth.m | ⊢ 𝑀  ∈  ℕ | 
						
							| 2 |  | ballotth.n | ⊢ 𝑁  ∈  ℕ | 
						
							| 3 |  | ballotth.o | ⊢ 𝑂  =  { 𝑐  ∈  𝒫  ( 1 ... ( 𝑀  +  𝑁 ) )  ∣  ( ♯ ‘ 𝑐 )  =  𝑀 } | 
						
							| 4 |  | ballotth.p | ⊢ 𝑃  =  ( 𝑥  ∈  𝒫  𝑂  ↦  ( ( ♯ ‘ 𝑥 )  /  ( ♯ ‘ 𝑂 ) ) ) | 
						
							| 5 |  | ballotth.f | ⊢ 𝐹  =  ( 𝑐  ∈  𝑂  ↦  ( 𝑖  ∈  ℤ  ↦  ( ( ♯ ‘ ( ( 1 ... 𝑖 )  ∩  𝑐 ) )  −  ( ♯ ‘ ( ( 1 ... 𝑖 )  ∖  𝑐 ) ) ) ) ) | 
						
							| 6 |  | ballotth.e | ⊢ 𝐸  =  { 𝑐  ∈  𝑂  ∣  ∀ 𝑖  ∈  ( 1 ... ( 𝑀  +  𝑁 ) ) 0  <  ( ( 𝐹 ‘ 𝑐 ) ‘ 𝑖 ) } | 
						
							| 7 |  | ballotth.mgtn | ⊢ 𝑁  <  𝑀 | 
						
							| 8 |  | ballotth.i | ⊢ 𝐼  =  ( 𝑐  ∈  ( 𝑂  ∖  𝐸 )  ↦  inf ( { 𝑘  ∈  ( 1 ... ( 𝑀  +  𝑁 ) )  ∣  ( ( 𝐹 ‘ 𝑐 ) ‘ 𝑘 )  =  0 } ,  ℝ ,   <  ) ) | 
						
							| 9 |  | ballotth.s | ⊢ 𝑆  =  ( 𝑐  ∈  ( 𝑂  ∖  𝐸 )  ↦  ( 𝑖  ∈  ( 1 ... ( 𝑀  +  𝑁 ) )  ↦  if ( 𝑖  ≤  ( 𝐼 ‘ 𝑐 ) ,  ( ( ( 𝐼 ‘ 𝑐 )  +  1 )  −  𝑖 ) ,  𝑖 ) ) ) | 
						
							| 10 |  | ballotth.r | ⊢ 𝑅  =  ( 𝑐  ∈  ( 𝑂  ∖  𝐸 )  ↦  ( ( 𝑆 ‘ 𝑐 )  “  𝑐 ) ) | 
						
							| 11 |  | simpl | ⊢ ( ( 𝐶  ∈  ( 𝑂  ∖  𝐸 )  ∧  𝐽  ∈  ( 1 ... ( 𝑀  +  𝑁 ) ) )  →  𝐶  ∈  ( 𝑂  ∖  𝐸 ) ) | 
						
							| 12 | 1 2 3 4 5 6 7 8 9 | ballotlemsf1o | ⊢ ( 𝐶  ∈  ( 𝑂  ∖  𝐸 )  →  ( ( 𝑆 ‘ 𝐶 ) : ( 1 ... ( 𝑀  +  𝑁 ) ) –1-1-onto→ ( 1 ... ( 𝑀  +  𝑁 ) )  ∧  ◡ ( 𝑆 ‘ 𝐶 )  =  ( 𝑆 ‘ 𝐶 ) ) ) | 
						
							| 13 | 12 | simpld | ⊢ ( 𝐶  ∈  ( 𝑂  ∖  𝐸 )  →  ( 𝑆 ‘ 𝐶 ) : ( 1 ... ( 𝑀  +  𝑁 ) ) –1-1-onto→ ( 1 ... ( 𝑀  +  𝑁 ) ) ) | 
						
							| 14 |  | f1ofun | ⊢ ( ( 𝑆 ‘ 𝐶 ) : ( 1 ... ( 𝑀  +  𝑁 ) ) –1-1-onto→ ( 1 ... ( 𝑀  +  𝑁 ) )  →  Fun  ( 𝑆 ‘ 𝐶 ) ) | 
						
							| 15 | 11 13 14 | 3syl | ⊢ ( ( 𝐶  ∈  ( 𝑂  ∖  𝐸 )  ∧  𝐽  ∈  ( 1 ... ( 𝑀  +  𝑁 ) ) )  →  Fun  ( 𝑆 ‘ 𝐶 ) ) | 
						
							| 16 |  | simpr | ⊢ ( ( 𝐶  ∈  ( 𝑂  ∖  𝐸 )  ∧  𝐽  ∈  ( 1 ... ( 𝑀  +  𝑁 ) ) )  →  𝐽  ∈  ( 1 ... ( 𝑀  +  𝑁 ) ) ) | 
						
							| 17 |  | f1odm | ⊢ ( ( 𝑆 ‘ 𝐶 ) : ( 1 ... ( 𝑀  +  𝑁 ) ) –1-1-onto→ ( 1 ... ( 𝑀  +  𝑁 ) )  →  dom  ( 𝑆 ‘ 𝐶 )  =  ( 1 ... ( 𝑀  +  𝑁 ) ) ) | 
						
							| 18 | 11 13 17 | 3syl | ⊢ ( ( 𝐶  ∈  ( 𝑂  ∖  𝐸 )  ∧  𝐽  ∈  ( 1 ... ( 𝑀  +  𝑁 ) ) )  →  dom  ( 𝑆 ‘ 𝐶 )  =  ( 1 ... ( 𝑀  +  𝑁 ) ) ) | 
						
							| 19 | 16 18 | eleqtrrd | ⊢ ( ( 𝐶  ∈  ( 𝑂  ∖  𝐸 )  ∧  𝐽  ∈  ( 1 ... ( 𝑀  +  𝑁 ) ) )  →  𝐽  ∈  dom  ( 𝑆 ‘ 𝐶 ) ) | 
						
							| 20 |  | fvimacnv | ⊢ ( ( Fun  ( 𝑆 ‘ 𝐶 )  ∧  𝐽  ∈  dom  ( 𝑆 ‘ 𝐶 ) )  →  ( ( ( 𝑆 ‘ 𝐶 ) ‘ 𝐽 )  ∈  𝐶  ↔  𝐽  ∈  ( ◡ ( 𝑆 ‘ 𝐶 )  “  𝐶 ) ) ) | 
						
							| 21 | 15 19 20 | syl2anc | ⊢ ( ( 𝐶  ∈  ( 𝑂  ∖  𝐸 )  ∧  𝐽  ∈  ( 1 ... ( 𝑀  +  𝑁 ) ) )  →  ( ( ( 𝑆 ‘ 𝐶 ) ‘ 𝐽 )  ∈  𝐶  ↔  𝐽  ∈  ( ◡ ( 𝑆 ‘ 𝐶 )  “  𝐶 ) ) ) | 
						
							| 22 | 1 2 3 4 5 6 7 8 9 | ballotlemsv | ⊢ ( ( 𝐶  ∈  ( 𝑂  ∖  𝐸 )  ∧  𝐽  ∈  ( 1 ... ( 𝑀  +  𝑁 ) ) )  →  ( ( 𝑆 ‘ 𝐶 ) ‘ 𝐽 )  =  if ( 𝐽  ≤  ( 𝐼 ‘ 𝐶 ) ,  ( ( ( 𝐼 ‘ 𝐶 )  +  1 )  −  𝐽 ) ,  𝐽 ) ) | 
						
							| 23 | 22 | eleq1d | ⊢ ( ( 𝐶  ∈  ( 𝑂  ∖  𝐸 )  ∧  𝐽  ∈  ( 1 ... ( 𝑀  +  𝑁 ) ) )  →  ( ( ( 𝑆 ‘ 𝐶 ) ‘ 𝐽 )  ∈  𝐶  ↔  if ( 𝐽  ≤  ( 𝐼 ‘ 𝐶 ) ,  ( ( ( 𝐼 ‘ 𝐶 )  +  1 )  −  𝐽 ) ,  𝐽 )  ∈  𝐶 ) ) | 
						
							| 24 | 12 | simprd | ⊢ ( 𝐶  ∈  ( 𝑂  ∖  𝐸 )  →  ◡ ( 𝑆 ‘ 𝐶 )  =  ( 𝑆 ‘ 𝐶 ) ) | 
						
							| 25 | 24 | imaeq1d | ⊢ ( 𝐶  ∈  ( 𝑂  ∖  𝐸 )  →  ( ◡ ( 𝑆 ‘ 𝐶 )  “  𝐶 )  =  ( ( 𝑆 ‘ 𝐶 )  “  𝐶 ) ) | 
						
							| 26 | 1 2 3 4 5 6 7 8 9 10 | ballotlemrval | ⊢ ( 𝐶  ∈  ( 𝑂  ∖  𝐸 )  →  ( 𝑅 ‘ 𝐶 )  =  ( ( 𝑆 ‘ 𝐶 )  “  𝐶 ) ) | 
						
							| 27 | 25 26 | eqtr4d | ⊢ ( 𝐶  ∈  ( 𝑂  ∖  𝐸 )  →  ( ◡ ( 𝑆 ‘ 𝐶 )  “  𝐶 )  =  ( 𝑅 ‘ 𝐶 ) ) | 
						
							| 28 | 27 | eleq2d | ⊢ ( 𝐶  ∈  ( 𝑂  ∖  𝐸 )  →  ( 𝐽  ∈  ( ◡ ( 𝑆 ‘ 𝐶 )  “  𝐶 )  ↔  𝐽  ∈  ( 𝑅 ‘ 𝐶 ) ) ) | 
						
							| 29 | 11 28 | syl | ⊢ ( ( 𝐶  ∈  ( 𝑂  ∖  𝐸 )  ∧  𝐽  ∈  ( 1 ... ( 𝑀  +  𝑁 ) ) )  →  ( 𝐽  ∈  ( ◡ ( 𝑆 ‘ 𝐶 )  “  𝐶 )  ↔  𝐽  ∈  ( 𝑅 ‘ 𝐶 ) ) ) | 
						
							| 30 | 21 23 29 | 3bitr3rd | ⊢ ( ( 𝐶  ∈  ( 𝑂  ∖  𝐸 )  ∧  𝐽  ∈  ( 1 ... ( 𝑀  +  𝑁 ) ) )  →  ( 𝐽  ∈  ( 𝑅 ‘ 𝐶 )  ↔  if ( 𝐽  ≤  ( 𝐼 ‘ 𝐶 ) ,  ( ( ( 𝐼 ‘ 𝐶 )  +  1 )  −  𝐽 ) ,  𝐽 )  ∈  𝐶 ) ) |