| Step | Hyp | Ref | Expression | 
						
							| 1 |  | psgnfzto1st.d | ⊢ 𝐷  =  ( 1 ... 𝑁 ) | 
						
							| 2 |  | psgnfzto1st.p | ⊢ 𝑃  =  ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝐼 ,  if ( 𝑖  ≤  𝐼 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) | 
						
							| 3 |  | psgnfzto1st.g | ⊢ 𝐺  =  ( SymGrp ‘ 𝐷 ) | 
						
							| 4 |  | psgnfzto1st.b | ⊢ 𝐵  =  ( Base ‘ 𝐺 ) | 
						
							| 5 |  | psgnfzto1st.s | ⊢ 𝑆  =  ( pmSgn ‘ 𝐷 ) | 
						
							| 6 |  | elfz1b | ⊢ ( 𝐼  ∈  ( 1 ... 𝑁 )  ↔  ( 𝐼  ∈  ℕ  ∧  𝑁  ∈  ℕ  ∧  𝐼  ≤  𝑁 ) ) | 
						
							| 7 | 6 | biimpi | ⊢ ( 𝐼  ∈  ( 1 ... 𝑁 )  →  ( 𝐼  ∈  ℕ  ∧  𝑁  ∈  ℕ  ∧  𝐼  ≤  𝑁 ) ) | 
						
							| 8 | 7 1 | eleq2s | ⊢ ( 𝐼  ∈  𝐷  →  ( 𝐼  ∈  ℕ  ∧  𝑁  ∈  ℕ  ∧  𝐼  ≤  𝑁 ) ) | 
						
							| 9 |  | 3ancoma | ⊢ ( ( 𝑁  ∈  ℕ  ∧  𝐼  ∈  ℕ  ∧  𝐼  ≤  𝑁 )  ↔  ( 𝐼  ∈  ℕ  ∧  𝑁  ∈  ℕ  ∧  𝐼  ≤  𝑁 ) ) | 
						
							| 10 | 8 9 | sylibr | ⊢ ( 𝐼  ∈  𝐷  →  ( 𝑁  ∈  ℕ  ∧  𝐼  ∈  ℕ  ∧  𝐼  ≤  𝑁 ) ) | 
						
							| 11 |  | df-3an | ⊢ ( ( 𝑁  ∈  ℕ  ∧  𝐼  ∈  ℕ  ∧  𝐼  ≤  𝑁 )  ↔  ( ( 𝑁  ∈  ℕ  ∧  𝐼  ∈  ℕ )  ∧  𝐼  ≤  𝑁 ) ) | 
						
							| 12 |  | breq1 | ⊢ ( 𝑚  =  1  →  ( 𝑚  ≤  𝑁  ↔  1  ≤  𝑁 ) ) | 
						
							| 13 |  | id | ⊢ ( 𝑚  =  1  →  𝑚  =  1 ) | 
						
							| 14 |  | breq2 | ⊢ ( 𝑚  =  1  →  ( 𝑖  ≤  𝑚  ↔  𝑖  ≤  1 ) ) | 
						
							| 15 | 14 | ifbid | ⊢ ( 𝑚  =  1  →  if ( 𝑖  ≤  𝑚 ,  ( 𝑖  −  1 ) ,  𝑖 )  =  if ( 𝑖  ≤  1 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) | 
						
							| 16 | 13 15 | ifeq12d | ⊢ ( 𝑚  =  1  →  if ( 𝑖  =  1 ,  𝑚 ,  if ( 𝑖  ≤  𝑚 ,  ( 𝑖  −  1 ) ,  𝑖 ) )  =  if ( 𝑖  =  1 ,  1 ,  if ( 𝑖  ≤  1 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) | 
						
							| 17 | 16 | mpteq2dv | ⊢ ( 𝑚  =  1  →  ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑚 ,  if ( 𝑖  ≤  𝑚 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) )  =  ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  1 ,  if ( 𝑖  ≤  1 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) ) | 
						
							| 18 | 17 | fveq2d | ⊢ ( 𝑚  =  1  →  ( 𝑆 ‘ ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑚 ,  if ( 𝑖  ≤  𝑚 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) )  =  ( 𝑆 ‘ ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  1 ,  if ( 𝑖  ≤  1 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) ) ) | 
						
							| 19 |  | oveq1 | ⊢ ( 𝑚  =  1  →  ( 𝑚  +  1 )  =  ( 1  +  1 ) ) | 
						
							| 20 | 19 | oveq2d | ⊢ ( 𝑚  =  1  →  ( - 1 ↑ ( 𝑚  +  1 ) )  =  ( - 1 ↑ ( 1  +  1 ) ) ) | 
						
							| 21 | 18 20 | eqeq12d | ⊢ ( 𝑚  =  1  →  ( ( 𝑆 ‘ ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑚 ,  if ( 𝑖  ≤  𝑚 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) )  =  ( - 1 ↑ ( 𝑚  +  1 ) )  ↔  ( 𝑆 ‘ ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  1 ,  if ( 𝑖  ≤  1 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) )  =  ( - 1 ↑ ( 1  +  1 ) ) ) ) | 
						
							| 22 | 12 21 | imbi12d | ⊢ ( 𝑚  =  1  →  ( ( 𝑚  ≤  𝑁  →  ( 𝑆 ‘ ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑚 ,  if ( 𝑖  ≤  𝑚 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) )  =  ( - 1 ↑ ( 𝑚  +  1 ) ) )  ↔  ( 1  ≤  𝑁  →  ( 𝑆 ‘ ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  1 ,  if ( 𝑖  ≤  1 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) )  =  ( - 1 ↑ ( 1  +  1 ) ) ) ) ) | 
						
							| 23 |  | breq1 | ⊢ ( 𝑚  =  𝑛  →  ( 𝑚  ≤  𝑁  ↔  𝑛  ≤  𝑁 ) ) | 
						
							| 24 |  | id | ⊢ ( 𝑚  =  𝑛  →  𝑚  =  𝑛 ) | 
						
							| 25 |  | breq2 | ⊢ ( 𝑚  =  𝑛  →  ( 𝑖  ≤  𝑚  ↔  𝑖  ≤  𝑛 ) ) | 
						
							| 26 | 25 | ifbid | ⊢ ( 𝑚  =  𝑛  →  if ( 𝑖  ≤  𝑚 ,  ( 𝑖  −  1 ) ,  𝑖 )  =  if ( 𝑖  ≤  𝑛 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) | 
						
							| 27 | 24 26 | ifeq12d | ⊢ ( 𝑚  =  𝑛  →  if ( 𝑖  =  1 ,  𝑚 ,  if ( 𝑖  ≤  𝑚 ,  ( 𝑖  −  1 ) ,  𝑖 ) )  =  if ( 𝑖  =  1 ,  𝑛 ,  if ( 𝑖  ≤  𝑛 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) | 
						
							| 28 | 27 | mpteq2dv | ⊢ ( 𝑚  =  𝑛  →  ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑚 ,  if ( 𝑖  ≤  𝑚 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) )  =  ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑛 ,  if ( 𝑖  ≤  𝑛 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) ) | 
						
							| 29 | 28 | fveq2d | ⊢ ( 𝑚  =  𝑛  →  ( 𝑆 ‘ ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑚 ,  if ( 𝑖  ≤  𝑚 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) )  =  ( 𝑆 ‘ ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑛 ,  if ( 𝑖  ≤  𝑛 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) ) ) | 
						
							| 30 |  | oveq1 | ⊢ ( 𝑚  =  𝑛  →  ( 𝑚  +  1 )  =  ( 𝑛  +  1 ) ) | 
						
							| 31 | 30 | oveq2d | ⊢ ( 𝑚  =  𝑛  →  ( - 1 ↑ ( 𝑚  +  1 ) )  =  ( - 1 ↑ ( 𝑛  +  1 ) ) ) | 
						
							| 32 | 29 31 | eqeq12d | ⊢ ( 𝑚  =  𝑛  →  ( ( 𝑆 ‘ ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑚 ,  if ( 𝑖  ≤  𝑚 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) )  =  ( - 1 ↑ ( 𝑚  +  1 ) )  ↔  ( 𝑆 ‘ ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑛 ,  if ( 𝑖  ≤  𝑛 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) )  =  ( - 1 ↑ ( 𝑛  +  1 ) ) ) ) | 
						
							| 33 | 23 32 | imbi12d | ⊢ ( 𝑚  =  𝑛  →  ( ( 𝑚  ≤  𝑁  →  ( 𝑆 ‘ ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑚 ,  if ( 𝑖  ≤  𝑚 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) )  =  ( - 1 ↑ ( 𝑚  +  1 ) ) )  ↔  ( 𝑛  ≤  𝑁  →  ( 𝑆 ‘ ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑛 ,  if ( 𝑖  ≤  𝑛 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) )  =  ( - 1 ↑ ( 𝑛  +  1 ) ) ) ) ) | 
						
							| 34 |  | breq1 | ⊢ ( 𝑚  =  ( 𝑛  +  1 )  →  ( 𝑚  ≤  𝑁  ↔  ( 𝑛  +  1 )  ≤  𝑁 ) ) | 
						
							| 35 |  | id | ⊢ ( 𝑚  =  ( 𝑛  +  1 )  →  𝑚  =  ( 𝑛  +  1 ) ) | 
						
							| 36 |  | breq2 | ⊢ ( 𝑚  =  ( 𝑛  +  1 )  →  ( 𝑖  ≤  𝑚  ↔  𝑖  ≤  ( 𝑛  +  1 ) ) ) | 
						
							| 37 | 36 | ifbid | ⊢ ( 𝑚  =  ( 𝑛  +  1 )  →  if ( 𝑖  ≤  𝑚 ,  ( 𝑖  −  1 ) ,  𝑖 )  =  if ( 𝑖  ≤  ( 𝑛  +  1 ) ,  ( 𝑖  −  1 ) ,  𝑖 ) ) | 
						
							| 38 | 35 37 | ifeq12d | ⊢ ( 𝑚  =  ( 𝑛  +  1 )  →  if ( 𝑖  =  1 ,  𝑚 ,  if ( 𝑖  ≤  𝑚 ,  ( 𝑖  −  1 ) ,  𝑖 ) )  =  if ( 𝑖  =  1 ,  ( 𝑛  +  1 ) ,  if ( 𝑖  ≤  ( 𝑛  +  1 ) ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) | 
						
							| 39 | 38 | mpteq2dv | ⊢ ( 𝑚  =  ( 𝑛  +  1 )  →  ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑚 ,  if ( 𝑖  ≤  𝑚 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) )  =  ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  ( 𝑛  +  1 ) ,  if ( 𝑖  ≤  ( 𝑛  +  1 ) ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) ) | 
						
							| 40 | 39 | fveq2d | ⊢ ( 𝑚  =  ( 𝑛  +  1 )  →  ( 𝑆 ‘ ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑚 ,  if ( 𝑖  ≤  𝑚 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) )  =  ( 𝑆 ‘ ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  ( 𝑛  +  1 ) ,  if ( 𝑖  ≤  ( 𝑛  +  1 ) ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) ) ) | 
						
							| 41 |  | oveq1 | ⊢ ( 𝑚  =  ( 𝑛  +  1 )  →  ( 𝑚  +  1 )  =  ( ( 𝑛  +  1 )  +  1 ) ) | 
						
							| 42 | 41 | oveq2d | ⊢ ( 𝑚  =  ( 𝑛  +  1 )  →  ( - 1 ↑ ( 𝑚  +  1 ) )  =  ( - 1 ↑ ( ( 𝑛  +  1 )  +  1 ) ) ) | 
						
							| 43 | 40 42 | eqeq12d | ⊢ ( 𝑚  =  ( 𝑛  +  1 )  →  ( ( 𝑆 ‘ ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑚 ,  if ( 𝑖  ≤  𝑚 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) )  =  ( - 1 ↑ ( 𝑚  +  1 ) )  ↔  ( 𝑆 ‘ ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  ( 𝑛  +  1 ) ,  if ( 𝑖  ≤  ( 𝑛  +  1 ) ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) )  =  ( - 1 ↑ ( ( 𝑛  +  1 )  +  1 ) ) ) ) | 
						
							| 44 | 34 43 | imbi12d | ⊢ ( 𝑚  =  ( 𝑛  +  1 )  →  ( ( 𝑚  ≤  𝑁  →  ( 𝑆 ‘ ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑚 ,  if ( 𝑖  ≤  𝑚 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) )  =  ( - 1 ↑ ( 𝑚  +  1 ) ) )  ↔  ( ( 𝑛  +  1 )  ≤  𝑁  →  ( 𝑆 ‘ ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  ( 𝑛  +  1 ) ,  if ( 𝑖  ≤  ( 𝑛  +  1 ) ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) )  =  ( - 1 ↑ ( ( 𝑛  +  1 )  +  1 ) ) ) ) ) | 
						
							| 45 |  | breq1 | ⊢ ( 𝑚  =  𝐼  →  ( 𝑚  ≤  𝑁  ↔  𝐼  ≤  𝑁 ) ) | 
						
							| 46 |  | id | ⊢ ( 𝑚  =  𝐼  →  𝑚  =  𝐼 ) | 
						
							| 47 |  | breq2 | ⊢ ( 𝑚  =  𝐼  →  ( 𝑖  ≤  𝑚  ↔  𝑖  ≤  𝐼 ) ) | 
						
							| 48 | 47 | ifbid | ⊢ ( 𝑚  =  𝐼  →  if ( 𝑖  ≤  𝑚 ,  ( 𝑖  −  1 ) ,  𝑖 )  =  if ( 𝑖  ≤  𝐼 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) | 
						
							| 49 | 46 48 | ifeq12d | ⊢ ( 𝑚  =  𝐼  →  if ( 𝑖  =  1 ,  𝑚 ,  if ( 𝑖  ≤  𝑚 ,  ( 𝑖  −  1 ) ,  𝑖 ) )  =  if ( 𝑖  =  1 ,  𝐼 ,  if ( 𝑖  ≤  𝐼 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) | 
						
							| 50 | 49 | mpteq2dv | ⊢ ( 𝑚  =  𝐼  →  ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑚 ,  if ( 𝑖  ≤  𝑚 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) )  =  ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝐼 ,  if ( 𝑖  ≤  𝐼 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) ) | 
						
							| 51 | 50 2 | eqtr4di | ⊢ ( 𝑚  =  𝐼  →  ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑚 ,  if ( 𝑖  ≤  𝑚 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) )  =  𝑃 ) | 
						
							| 52 | 51 | fveq2d | ⊢ ( 𝑚  =  𝐼  →  ( 𝑆 ‘ ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑚 ,  if ( 𝑖  ≤  𝑚 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) )  =  ( 𝑆 ‘ 𝑃 ) ) | 
						
							| 53 |  | oveq1 | ⊢ ( 𝑚  =  𝐼  →  ( 𝑚  +  1 )  =  ( 𝐼  +  1 ) ) | 
						
							| 54 | 53 | oveq2d | ⊢ ( 𝑚  =  𝐼  →  ( - 1 ↑ ( 𝑚  +  1 ) )  =  ( - 1 ↑ ( 𝐼  +  1 ) ) ) | 
						
							| 55 | 52 54 | eqeq12d | ⊢ ( 𝑚  =  𝐼  →  ( ( 𝑆 ‘ ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑚 ,  if ( 𝑖  ≤  𝑚 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) )  =  ( - 1 ↑ ( 𝑚  +  1 ) )  ↔  ( 𝑆 ‘ 𝑃 )  =  ( - 1 ↑ ( 𝐼  +  1 ) ) ) ) | 
						
							| 56 | 45 55 | imbi12d | ⊢ ( 𝑚  =  𝐼  →  ( ( 𝑚  ≤  𝑁  →  ( 𝑆 ‘ ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑚 ,  if ( 𝑖  ≤  𝑚 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) )  =  ( - 1 ↑ ( 𝑚  +  1 ) ) )  ↔  ( 𝐼  ≤  𝑁  →  ( 𝑆 ‘ 𝑃 )  =  ( - 1 ↑ ( 𝐼  +  1 ) ) ) ) ) | 
						
							| 57 |  | fzfi | ⊢ ( 1 ... 𝑁 )  ∈  Fin | 
						
							| 58 | 1 57 | eqeltri | ⊢ 𝐷  ∈  Fin | 
						
							| 59 | 5 | psgnid | ⊢ ( 𝐷  ∈  Fin  →  ( 𝑆 ‘ (  I   ↾  𝐷 ) )  =  1 ) | 
						
							| 60 | 58 59 | ax-mp | ⊢ ( 𝑆 ‘ (  I   ↾  𝐷 ) )  =  1 | 
						
							| 61 |  | eqid | ⊢ 1  =  1 | 
						
							| 62 |  | eqid | ⊢ ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  1 ,  if ( 𝑖  ≤  1 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) )  =  ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  1 ,  if ( 𝑖  ≤  1 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) | 
						
							| 63 | 1 62 | fzto1st1 | ⊢ ( 1  =  1  →  ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  1 ,  if ( 𝑖  ≤  1 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) )  =  (  I   ↾  𝐷 ) ) | 
						
							| 64 | 61 63 | ax-mp | ⊢ ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  1 ,  if ( 𝑖  ≤  1 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) )  =  (  I   ↾  𝐷 ) | 
						
							| 65 | 64 | fveq2i | ⊢ ( 𝑆 ‘ ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  1 ,  if ( 𝑖  ≤  1 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) )  =  ( 𝑆 ‘ (  I   ↾  𝐷 ) ) | 
						
							| 66 |  | 1p1e2 | ⊢ ( 1  +  1 )  =  2 | 
						
							| 67 | 66 | oveq2i | ⊢ ( - 1 ↑ ( 1  +  1 ) )  =  ( - 1 ↑ 2 ) | 
						
							| 68 |  | neg1sqe1 | ⊢ ( - 1 ↑ 2 )  =  1 | 
						
							| 69 | 67 68 | eqtri | ⊢ ( - 1 ↑ ( 1  +  1 ) )  =  1 | 
						
							| 70 | 60 65 69 | 3eqtr4i | ⊢ ( 𝑆 ‘ ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  1 ,  if ( 𝑖  ≤  1 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) )  =  ( - 1 ↑ ( 1  +  1 ) ) | 
						
							| 71 | 70 | 2a1i | ⊢ ( 𝑁  ∈  ℕ  →  ( 1  ≤  𝑁  →  ( 𝑆 ‘ ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  1 ,  if ( 𝑖  ≤  1 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) )  =  ( - 1 ↑ ( 1  +  1 ) ) ) ) | 
						
							| 72 |  | simplr | ⊢ ( ( ( 𝑁  ∈  ℕ  ∧  𝑛  ∈  ℕ )  ∧  ( 𝑛  +  1 )  ≤  𝑁 )  →  𝑛  ∈  ℕ ) | 
						
							| 73 | 72 | peano2nnd | ⊢ ( ( ( 𝑁  ∈  ℕ  ∧  𝑛  ∈  ℕ )  ∧  ( 𝑛  +  1 )  ≤  𝑁 )  →  ( 𝑛  +  1 )  ∈  ℕ ) | 
						
							| 74 |  | simpll | ⊢ ( ( ( 𝑁  ∈  ℕ  ∧  𝑛  ∈  ℕ )  ∧  ( 𝑛  +  1 )  ≤  𝑁 )  →  𝑁  ∈  ℕ ) | 
						
							| 75 |  | simpr | ⊢ ( ( ( 𝑁  ∈  ℕ  ∧  𝑛  ∈  ℕ )  ∧  ( 𝑛  +  1 )  ≤  𝑁 )  →  ( 𝑛  +  1 )  ≤  𝑁 ) | 
						
							| 76 | 73 74 75 | 3jca | ⊢ ( ( ( 𝑁  ∈  ℕ  ∧  𝑛  ∈  ℕ )  ∧  ( 𝑛  +  1 )  ≤  𝑁 )  →  ( ( 𝑛  +  1 )  ∈  ℕ  ∧  𝑁  ∈  ℕ  ∧  ( 𝑛  +  1 )  ≤  𝑁 ) ) | 
						
							| 77 |  | elfz1b | ⊢ ( ( 𝑛  +  1 )  ∈  ( 1 ... 𝑁 )  ↔  ( ( 𝑛  +  1 )  ∈  ℕ  ∧  𝑁  ∈  ℕ  ∧  ( 𝑛  +  1 )  ≤  𝑁 ) ) | 
						
							| 78 | 76 77 | sylibr | ⊢ ( ( ( 𝑁  ∈  ℕ  ∧  𝑛  ∈  ℕ )  ∧  ( 𝑛  +  1 )  ≤  𝑁 )  →  ( 𝑛  +  1 )  ∈  ( 1 ... 𝑁 ) ) | 
						
							| 79 | 78 1 | eleqtrrdi | ⊢ ( ( ( 𝑁  ∈  ℕ  ∧  𝑛  ∈  ℕ )  ∧  ( 𝑛  +  1 )  ≤  𝑁 )  →  ( 𝑛  +  1 )  ∈  𝐷 ) | 
						
							| 80 | 1 | psgnfzto1stlem | ⊢ ( ( 𝑛  ∈  ℕ  ∧  ( 𝑛  +  1 )  ∈  𝐷 )  →  ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  ( 𝑛  +  1 ) ,  if ( 𝑖  ≤  ( 𝑛  +  1 ) ,  ( 𝑖  −  1 ) ,  𝑖 ) ) )  =  ( ( ( pmTrsp ‘ 𝐷 ) ‘ { 𝑛 ,  ( 𝑛  +  1 ) } )  ∘  ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑛 ,  if ( 𝑖  ≤  𝑛 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) ) ) | 
						
							| 81 | 72 79 80 | syl2anc | ⊢ ( ( ( 𝑁  ∈  ℕ  ∧  𝑛  ∈  ℕ )  ∧  ( 𝑛  +  1 )  ≤  𝑁 )  →  ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  ( 𝑛  +  1 ) ,  if ( 𝑖  ≤  ( 𝑛  +  1 ) ,  ( 𝑖  −  1 ) ,  𝑖 ) ) )  =  ( ( ( pmTrsp ‘ 𝐷 ) ‘ { 𝑛 ,  ( 𝑛  +  1 ) } )  ∘  ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑛 ,  if ( 𝑖  ≤  𝑛 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) ) ) | 
						
							| 82 | 81 | adantlr | ⊢ ( ( ( ( 𝑁  ∈  ℕ  ∧  𝑛  ∈  ℕ )  ∧  ( 𝑛  ≤  𝑁  →  ( 𝑆 ‘ ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑛 ,  if ( 𝑖  ≤  𝑛 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) )  =  ( - 1 ↑ ( 𝑛  +  1 ) ) ) )  ∧  ( 𝑛  +  1 )  ≤  𝑁 )  →  ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  ( 𝑛  +  1 ) ,  if ( 𝑖  ≤  ( 𝑛  +  1 ) ,  ( 𝑖  −  1 ) ,  𝑖 ) ) )  =  ( ( ( pmTrsp ‘ 𝐷 ) ‘ { 𝑛 ,  ( 𝑛  +  1 ) } )  ∘  ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑛 ,  if ( 𝑖  ≤  𝑛 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) ) ) | 
						
							| 83 | 82 | fveq2d | ⊢ ( ( ( ( 𝑁  ∈  ℕ  ∧  𝑛  ∈  ℕ )  ∧  ( 𝑛  ≤  𝑁  →  ( 𝑆 ‘ ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑛 ,  if ( 𝑖  ≤  𝑛 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) )  =  ( - 1 ↑ ( 𝑛  +  1 ) ) ) )  ∧  ( 𝑛  +  1 )  ≤  𝑁 )  →  ( 𝑆 ‘ ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  ( 𝑛  +  1 ) ,  if ( 𝑖  ≤  ( 𝑛  +  1 ) ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) )  =  ( 𝑆 ‘ ( ( ( pmTrsp ‘ 𝐷 ) ‘ { 𝑛 ,  ( 𝑛  +  1 ) } )  ∘  ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑛 ,  if ( 𝑖  ≤  𝑛 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) ) ) ) | 
						
							| 84 | 58 | a1i | ⊢ ( ( ( ( 𝑁  ∈  ℕ  ∧  𝑛  ∈  ℕ )  ∧  ( 𝑛  ≤  𝑁  →  ( 𝑆 ‘ ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑛 ,  if ( 𝑖  ≤  𝑛 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) )  =  ( - 1 ↑ ( 𝑛  +  1 ) ) ) )  ∧  ( 𝑛  +  1 )  ≤  𝑁 )  →  𝐷  ∈  Fin ) | 
						
							| 85 |  | eqid | ⊢ ran  ( pmTrsp ‘ 𝐷 )  =  ran  ( pmTrsp ‘ 𝐷 ) | 
						
							| 86 | 85 3 4 | symgtrf | ⊢ ran  ( pmTrsp ‘ 𝐷 )  ⊆  𝐵 | 
						
							| 87 |  | eqid | ⊢ ( pmTrsp ‘ 𝐷 )  =  ( pmTrsp ‘ 𝐷 ) | 
						
							| 88 | 1 87 | pmtrto1cl | ⊢ ( ( 𝑛  ∈  ℕ  ∧  ( 𝑛  +  1 )  ∈  𝐷 )  →  ( ( pmTrsp ‘ 𝐷 ) ‘ { 𝑛 ,  ( 𝑛  +  1 ) } )  ∈  ran  ( pmTrsp ‘ 𝐷 ) ) | 
						
							| 89 | 72 79 88 | syl2anc | ⊢ ( ( ( 𝑁  ∈  ℕ  ∧  𝑛  ∈  ℕ )  ∧  ( 𝑛  +  1 )  ≤  𝑁 )  →  ( ( pmTrsp ‘ 𝐷 ) ‘ { 𝑛 ,  ( 𝑛  +  1 ) } )  ∈  ran  ( pmTrsp ‘ 𝐷 ) ) | 
						
							| 90 | 89 | adantlr | ⊢ ( ( ( ( 𝑁  ∈  ℕ  ∧  𝑛  ∈  ℕ )  ∧  ( 𝑛  ≤  𝑁  →  ( 𝑆 ‘ ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑛 ,  if ( 𝑖  ≤  𝑛 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) )  =  ( - 1 ↑ ( 𝑛  +  1 ) ) ) )  ∧  ( 𝑛  +  1 )  ≤  𝑁 )  →  ( ( pmTrsp ‘ 𝐷 ) ‘ { 𝑛 ,  ( 𝑛  +  1 ) } )  ∈  ran  ( pmTrsp ‘ 𝐷 ) ) | 
						
							| 91 | 86 90 | sselid | ⊢ ( ( ( ( 𝑁  ∈  ℕ  ∧  𝑛  ∈  ℕ )  ∧  ( 𝑛  ≤  𝑁  →  ( 𝑆 ‘ ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑛 ,  if ( 𝑖  ≤  𝑛 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) )  =  ( - 1 ↑ ( 𝑛  +  1 ) ) ) )  ∧  ( 𝑛  +  1 )  ≤  𝑁 )  →  ( ( pmTrsp ‘ 𝐷 ) ‘ { 𝑛 ,  ( 𝑛  +  1 ) } )  ∈  𝐵 ) | 
						
							| 92 | 72 | nnred | ⊢ ( ( ( 𝑁  ∈  ℕ  ∧  𝑛  ∈  ℕ )  ∧  ( 𝑛  +  1 )  ≤  𝑁 )  →  𝑛  ∈  ℝ ) | 
						
							| 93 |  | 1red | ⊢ ( ( ( 𝑁  ∈  ℕ  ∧  𝑛  ∈  ℕ )  ∧  ( 𝑛  +  1 )  ≤  𝑁 )  →  1  ∈  ℝ ) | 
						
							| 94 | 92 93 | readdcld | ⊢ ( ( ( 𝑁  ∈  ℕ  ∧  𝑛  ∈  ℕ )  ∧  ( 𝑛  +  1 )  ≤  𝑁 )  →  ( 𝑛  +  1 )  ∈  ℝ ) | 
						
							| 95 | 74 | nnred | ⊢ ( ( ( 𝑁  ∈  ℕ  ∧  𝑛  ∈  ℕ )  ∧  ( 𝑛  +  1 )  ≤  𝑁 )  →  𝑁  ∈  ℝ ) | 
						
							| 96 | 92 | lep1d | ⊢ ( ( ( 𝑁  ∈  ℕ  ∧  𝑛  ∈  ℕ )  ∧  ( 𝑛  +  1 )  ≤  𝑁 )  →  𝑛  ≤  ( 𝑛  +  1 ) ) | 
						
							| 97 | 92 94 95 96 75 | letrd | ⊢ ( ( ( 𝑁  ∈  ℕ  ∧  𝑛  ∈  ℕ )  ∧  ( 𝑛  +  1 )  ≤  𝑁 )  →  𝑛  ≤  𝑁 ) | 
						
							| 98 | 72 74 97 | 3jca | ⊢ ( ( ( 𝑁  ∈  ℕ  ∧  𝑛  ∈  ℕ )  ∧  ( 𝑛  +  1 )  ≤  𝑁 )  →  ( 𝑛  ∈  ℕ  ∧  𝑁  ∈  ℕ  ∧  𝑛  ≤  𝑁 ) ) | 
						
							| 99 |  | elfz1b | ⊢ ( 𝑛  ∈  ( 1 ... 𝑁 )  ↔  ( 𝑛  ∈  ℕ  ∧  𝑁  ∈  ℕ  ∧  𝑛  ≤  𝑁 ) ) | 
						
							| 100 | 98 99 | sylibr | ⊢ ( ( ( 𝑁  ∈  ℕ  ∧  𝑛  ∈  ℕ )  ∧  ( 𝑛  +  1 )  ≤  𝑁 )  →  𝑛  ∈  ( 1 ... 𝑁 ) ) | 
						
							| 101 | 100 1 | eleqtrrdi | ⊢ ( ( ( 𝑁  ∈  ℕ  ∧  𝑛  ∈  ℕ )  ∧  ( 𝑛  +  1 )  ≤  𝑁 )  →  𝑛  ∈  𝐷 ) | 
						
							| 102 | 101 | adantlr | ⊢ ( ( ( ( 𝑁  ∈  ℕ  ∧  𝑛  ∈  ℕ )  ∧  ( 𝑛  ≤  𝑁  →  ( 𝑆 ‘ ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑛 ,  if ( 𝑖  ≤  𝑛 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) )  =  ( - 1 ↑ ( 𝑛  +  1 ) ) ) )  ∧  ( 𝑛  +  1 )  ≤  𝑁 )  →  𝑛  ∈  𝐷 ) | 
						
							| 103 |  | eqid | ⊢ ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑛 ,  if ( 𝑖  ≤  𝑛 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) )  =  ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑛 ,  if ( 𝑖  ≤  𝑛 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) | 
						
							| 104 | 1 103 3 4 | fzto1st | ⊢ ( 𝑛  ∈  𝐷  →  ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑛 ,  if ( 𝑖  ≤  𝑛 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) )  ∈  𝐵 ) | 
						
							| 105 | 102 104 | syl | ⊢ ( ( ( ( 𝑁  ∈  ℕ  ∧  𝑛  ∈  ℕ )  ∧  ( 𝑛  ≤  𝑁  →  ( 𝑆 ‘ ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑛 ,  if ( 𝑖  ≤  𝑛 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) )  =  ( - 1 ↑ ( 𝑛  +  1 ) ) ) )  ∧  ( 𝑛  +  1 )  ≤  𝑁 )  →  ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑛 ,  if ( 𝑖  ≤  𝑛 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) )  ∈  𝐵 ) | 
						
							| 106 | 3 5 4 | psgnco | ⊢ ( ( 𝐷  ∈  Fin  ∧  ( ( pmTrsp ‘ 𝐷 ) ‘ { 𝑛 ,  ( 𝑛  +  1 ) } )  ∈  𝐵  ∧  ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑛 ,  if ( 𝑖  ≤  𝑛 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) )  ∈  𝐵 )  →  ( 𝑆 ‘ ( ( ( pmTrsp ‘ 𝐷 ) ‘ { 𝑛 ,  ( 𝑛  +  1 ) } )  ∘  ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑛 ,  if ( 𝑖  ≤  𝑛 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) ) )  =  ( ( 𝑆 ‘ ( ( pmTrsp ‘ 𝐷 ) ‘ { 𝑛 ,  ( 𝑛  +  1 ) } ) )  ·  ( 𝑆 ‘ ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑛 ,  if ( 𝑖  ≤  𝑛 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) ) ) ) | 
						
							| 107 | 84 91 105 106 | syl3anc | ⊢ ( ( ( ( 𝑁  ∈  ℕ  ∧  𝑛  ∈  ℕ )  ∧  ( 𝑛  ≤  𝑁  →  ( 𝑆 ‘ ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑛 ,  if ( 𝑖  ≤  𝑛 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) )  =  ( - 1 ↑ ( 𝑛  +  1 ) ) ) )  ∧  ( 𝑛  +  1 )  ≤  𝑁 )  →  ( 𝑆 ‘ ( ( ( pmTrsp ‘ 𝐷 ) ‘ { 𝑛 ,  ( 𝑛  +  1 ) } )  ∘  ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑛 ,  if ( 𝑖  ≤  𝑛 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) ) )  =  ( ( 𝑆 ‘ ( ( pmTrsp ‘ 𝐷 ) ‘ { 𝑛 ,  ( 𝑛  +  1 ) } ) )  ·  ( 𝑆 ‘ ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑛 ,  if ( 𝑖  ≤  𝑛 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) ) ) ) | 
						
							| 108 | 3 85 5 | psgnpmtr | ⊢ ( ( ( pmTrsp ‘ 𝐷 ) ‘ { 𝑛 ,  ( 𝑛  +  1 ) } )  ∈  ran  ( pmTrsp ‘ 𝐷 )  →  ( 𝑆 ‘ ( ( pmTrsp ‘ 𝐷 ) ‘ { 𝑛 ,  ( 𝑛  +  1 ) } ) )  =  - 1 ) | 
						
							| 109 | 89 108 | syl | ⊢ ( ( ( 𝑁  ∈  ℕ  ∧  𝑛  ∈  ℕ )  ∧  ( 𝑛  +  1 )  ≤  𝑁 )  →  ( 𝑆 ‘ ( ( pmTrsp ‘ 𝐷 ) ‘ { 𝑛 ,  ( 𝑛  +  1 ) } ) )  =  - 1 ) | 
						
							| 110 | 109 | adantlr | ⊢ ( ( ( ( 𝑁  ∈  ℕ  ∧  𝑛  ∈  ℕ )  ∧  ( 𝑛  ≤  𝑁  →  ( 𝑆 ‘ ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑛 ,  if ( 𝑖  ≤  𝑛 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) )  =  ( - 1 ↑ ( 𝑛  +  1 ) ) ) )  ∧  ( 𝑛  +  1 )  ≤  𝑁 )  →  ( 𝑆 ‘ ( ( pmTrsp ‘ 𝐷 ) ‘ { 𝑛 ,  ( 𝑛  +  1 ) } ) )  =  - 1 ) | 
						
							| 111 | 97 | adantlr | ⊢ ( ( ( ( 𝑁  ∈  ℕ  ∧  𝑛  ∈  ℕ )  ∧  ( 𝑛  ≤  𝑁  →  ( 𝑆 ‘ ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑛 ,  if ( 𝑖  ≤  𝑛 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) )  =  ( - 1 ↑ ( 𝑛  +  1 ) ) ) )  ∧  ( 𝑛  +  1 )  ≤  𝑁 )  →  𝑛  ≤  𝑁 ) | 
						
							| 112 |  | simplr | ⊢ ( ( ( ( 𝑁  ∈  ℕ  ∧  𝑛  ∈  ℕ )  ∧  ( 𝑛  ≤  𝑁  →  ( 𝑆 ‘ ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑛 ,  if ( 𝑖  ≤  𝑛 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) )  =  ( - 1 ↑ ( 𝑛  +  1 ) ) ) )  ∧  ( 𝑛  +  1 )  ≤  𝑁 )  →  ( 𝑛  ≤  𝑁  →  ( 𝑆 ‘ ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑛 ,  if ( 𝑖  ≤  𝑛 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) )  =  ( - 1 ↑ ( 𝑛  +  1 ) ) ) ) | 
						
							| 113 | 111 112 | mpd | ⊢ ( ( ( ( 𝑁  ∈  ℕ  ∧  𝑛  ∈  ℕ )  ∧  ( 𝑛  ≤  𝑁  →  ( 𝑆 ‘ ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑛 ,  if ( 𝑖  ≤  𝑛 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) )  =  ( - 1 ↑ ( 𝑛  +  1 ) ) ) )  ∧  ( 𝑛  +  1 )  ≤  𝑁 )  →  ( 𝑆 ‘ ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑛 ,  if ( 𝑖  ≤  𝑛 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) )  =  ( - 1 ↑ ( 𝑛  +  1 ) ) ) | 
						
							| 114 | 110 113 | oveq12d | ⊢ ( ( ( ( 𝑁  ∈  ℕ  ∧  𝑛  ∈  ℕ )  ∧  ( 𝑛  ≤  𝑁  →  ( 𝑆 ‘ ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑛 ,  if ( 𝑖  ≤  𝑛 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) )  =  ( - 1 ↑ ( 𝑛  +  1 ) ) ) )  ∧  ( 𝑛  +  1 )  ≤  𝑁 )  →  ( ( 𝑆 ‘ ( ( pmTrsp ‘ 𝐷 ) ‘ { 𝑛 ,  ( 𝑛  +  1 ) } ) )  ·  ( 𝑆 ‘ ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑛 ,  if ( 𝑖  ≤  𝑛 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) ) )  =  ( - 1  ·  ( - 1 ↑ ( 𝑛  +  1 ) ) ) ) | 
						
							| 115 |  | neg1cn | ⊢ - 1  ∈  ℂ | 
						
							| 116 |  | peano2nn | ⊢ ( 𝑛  ∈  ℕ  →  ( 𝑛  +  1 )  ∈  ℕ ) | 
						
							| 117 | 116 | nnnn0d | ⊢ ( 𝑛  ∈  ℕ  →  ( 𝑛  +  1 )  ∈  ℕ0 ) | 
						
							| 118 |  | expp1 | ⊢ ( ( - 1  ∈  ℂ  ∧  ( 𝑛  +  1 )  ∈  ℕ0 )  →  ( - 1 ↑ ( ( 𝑛  +  1 )  +  1 ) )  =  ( ( - 1 ↑ ( 𝑛  +  1 ) )  ·  - 1 ) ) | 
						
							| 119 | 115 117 118 | sylancr | ⊢ ( 𝑛  ∈  ℕ  →  ( - 1 ↑ ( ( 𝑛  +  1 )  +  1 ) )  =  ( ( - 1 ↑ ( 𝑛  +  1 ) )  ·  - 1 ) ) | 
						
							| 120 | 115 | a1i | ⊢ ( 𝑛  ∈  ℕ  →  - 1  ∈  ℂ ) | 
						
							| 121 | 120 117 | expcld | ⊢ ( 𝑛  ∈  ℕ  →  ( - 1 ↑ ( 𝑛  +  1 ) )  ∈  ℂ ) | 
						
							| 122 | 121 120 | mulcomd | ⊢ ( 𝑛  ∈  ℕ  →  ( ( - 1 ↑ ( 𝑛  +  1 ) )  ·  - 1 )  =  ( - 1  ·  ( - 1 ↑ ( 𝑛  +  1 ) ) ) ) | 
						
							| 123 | 119 122 | eqtr2d | ⊢ ( 𝑛  ∈  ℕ  →  ( - 1  ·  ( - 1 ↑ ( 𝑛  +  1 ) ) )  =  ( - 1 ↑ ( ( 𝑛  +  1 )  +  1 ) ) ) | 
						
							| 124 | 123 | ad3antlr | ⊢ ( ( ( ( 𝑁  ∈  ℕ  ∧  𝑛  ∈  ℕ )  ∧  ( 𝑛  ≤  𝑁  →  ( 𝑆 ‘ ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑛 ,  if ( 𝑖  ≤  𝑛 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) )  =  ( - 1 ↑ ( 𝑛  +  1 ) ) ) )  ∧  ( 𝑛  +  1 )  ≤  𝑁 )  →  ( - 1  ·  ( - 1 ↑ ( 𝑛  +  1 ) ) )  =  ( - 1 ↑ ( ( 𝑛  +  1 )  +  1 ) ) ) | 
						
							| 125 | 114 124 | eqtrd | ⊢ ( ( ( ( 𝑁  ∈  ℕ  ∧  𝑛  ∈  ℕ )  ∧  ( 𝑛  ≤  𝑁  →  ( 𝑆 ‘ ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑛 ,  if ( 𝑖  ≤  𝑛 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) )  =  ( - 1 ↑ ( 𝑛  +  1 ) ) ) )  ∧  ( 𝑛  +  1 )  ≤  𝑁 )  →  ( ( 𝑆 ‘ ( ( pmTrsp ‘ 𝐷 ) ‘ { 𝑛 ,  ( 𝑛  +  1 ) } ) )  ·  ( 𝑆 ‘ ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑛 ,  if ( 𝑖  ≤  𝑛 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) ) )  =  ( - 1 ↑ ( ( 𝑛  +  1 )  +  1 ) ) ) | 
						
							| 126 | 83 107 125 | 3eqtrd | ⊢ ( ( ( ( 𝑁  ∈  ℕ  ∧  𝑛  ∈  ℕ )  ∧  ( 𝑛  ≤  𝑁  →  ( 𝑆 ‘ ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑛 ,  if ( 𝑖  ≤  𝑛 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) )  =  ( - 1 ↑ ( 𝑛  +  1 ) ) ) )  ∧  ( 𝑛  +  1 )  ≤  𝑁 )  →  ( 𝑆 ‘ ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  ( 𝑛  +  1 ) ,  if ( 𝑖  ≤  ( 𝑛  +  1 ) ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) )  =  ( - 1 ↑ ( ( 𝑛  +  1 )  +  1 ) ) ) | 
						
							| 127 | 126 | ex | ⊢ ( ( ( 𝑁  ∈  ℕ  ∧  𝑛  ∈  ℕ )  ∧  ( 𝑛  ≤  𝑁  →  ( 𝑆 ‘ ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  𝑛 ,  if ( 𝑖  ≤  𝑛 ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) )  =  ( - 1 ↑ ( 𝑛  +  1 ) ) ) )  →  ( ( 𝑛  +  1 )  ≤  𝑁  →  ( 𝑆 ‘ ( 𝑖  ∈  𝐷  ↦  if ( 𝑖  =  1 ,  ( 𝑛  +  1 ) ,  if ( 𝑖  ≤  ( 𝑛  +  1 ) ,  ( 𝑖  −  1 ) ,  𝑖 ) ) ) )  =  ( - 1 ↑ ( ( 𝑛  +  1 )  +  1 ) ) ) ) | 
						
							| 128 | 22 33 44 56 71 127 | nnindd | ⊢ ( ( 𝑁  ∈  ℕ  ∧  𝐼  ∈  ℕ )  →  ( 𝐼  ≤  𝑁  →  ( 𝑆 ‘ 𝑃 )  =  ( - 1 ↑ ( 𝐼  +  1 ) ) ) ) | 
						
							| 129 | 128 | imp | ⊢ ( ( ( 𝑁  ∈  ℕ  ∧  𝐼  ∈  ℕ )  ∧  𝐼  ≤  𝑁 )  →  ( 𝑆 ‘ 𝑃 )  =  ( - 1 ↑ ( 𝐼  +  1 ) ) ) | 
						
							| 130 | 11 129 | sylbi | ⊢ ( ( 𝑁  ∈  ℕ  ∧  𝐼  ∈  ℕ  ∧  𝐼  ≤  𝑁 )  →  ( 𝑆 ‘ 𝑃 )  =  ( - 1 ↑ ( 𝐼  +  1 ) ) ) | 
						
							| 131 | 10 130 | syl | ⊢ ( 𝐼  ∈  𝐷  →  ( 𝑆 ‘ 𝑃 )  =  ( - 1 ↑ ( 𝐼  +  1 ) ) ) |