| Step | Hyp | Ref | Expression | 
						
							| 1 |  | signsv.p | ⊢  ⨣   =  ( 𝑎  ∈  { - 1 ,  0 ,  1 } ,  𝑏  ∈  { - 1 ,  0 ,  1 }  ↦  if ( 𝑏  =  0 ,  𝑎 ,  𝑏 ) ) | 
						
							| 2 |  | signsv.w | ⊢ 𝑊  =  { 〈 ( Base ‘ ndx ) ,  { - 1 ,  0 ,  1 } 〉 ,  〈 ( +g ‘ ndx ) ,   ⨣  〉 } | 
						
							| 3 |  | signsv.t | ⊢ 𝑇  =  ( 𝑓  ∈  Word  ℝ  ↦  ( 𝑛  ∈  ( 0 ..^ ( ♯ ‘ 𝑓 ) )  ↦  ( 𝑊  Σg  ( 𝑖  ∈  ( 0 ... 𝑛 )  ↦  ( sgn ‘ ( 𝑓 ‘ 𝑖 ) ) ) ) ) ) | 
						
							| 4 |  | signsv.v | ⊢ 𝑉  =  ( 𝑓  ∈  Word  ℝ  ↦  Σ 𝑗  ∈  ( 1 ..^ ( ♯ ‘ 𝑓 ) ) if ( ( ( 𝑇 ‘ 𝑓 ) ‘ 𝑗 )  ≠  ( ( 𝑇 ‘ 𝑓 ) ‘ ( 𝑗  −  1 ) ) ,  1 ,  0 ) ) | 
						
							| 5 | 1 2 | signswbase | ⊢ { - 1 ,  0 ,  1 }  =  ( Base ‘ 𝑊 ) | 
						
							| 6 | 1 2 | signswmnd | ⊢ 𝑊  ∈  Mnd | 
						
							| 7 | 6 | a1i | ⊢ ( ( 𝐹  ∈  ( Word  ℝ  ∖  { ∅ } )  ∧  𝐾  ∈  ℝ )  →  𝑊  ∈  Mnd ) | 
						
							| 8 |  | eldifi | ⊢ ( 𝐹  ∈  ( Word  ℝ  ∖  { ∅ } )  →  𝐹  ∈  Word  ℝ ) | 
						
							| 9 |  | lencl | ⊢ ( 𝐹  ∈  Word  ℝ  →  ( ♯ ‘ 𝐹 )  ∈  ℕ0 ) | 
						
							| 10 | 8 9 | syl | ⊢ ( 𝐹  ∈  ( Word  ℝ  ∖  { ∅ } )  →  ( ♯ ‘ 𝐹 )  ∈  ℕ0 ) | 
						
							| 11 |  | eldifsn | ⊢ ( 𝐹  ∈  ( Word  ℝ  ∖  { ∅ } )  ↔  ( 𝐹  ∈  Word  ℝ  ∧  𝐹  ≠  ∅ ) ) | 
						
							| 12 |  | hasheq0 | ⊢ ( 𝐹  ∈  Word  ℝ  →  ( ( ♯ ‘ 𝐹 )  =  0  ↔  𝐹  =  ∅ ) ) | 
						
							| 13 | 12 | necon3bid | ⊢ ( 𝐹  ∈  Word  ℝ  →  ( ( ♯ ‘ 𝐹 )  ≠  0  ↔  𝐹  ≠  ∅ ) ) | 
						
							| 14 | 13 | biimpar | ⊢ ( ( 𝐹  ∈  Word  ℝ  ∧  𝐹  ≠  ∅ )  →  ( ♯ ‘ 𝐹 )  ≠  0 ) | 
						
							| 15 | 11 14 | sylbi | ⊢ ( 𝐹  ∈  ( Word  ℝ  ∖  { ∅ } )  →  ( ♯ ‘ 𝐹 )  ≠  0 ) | 
						
							| 16 |  | elnnne0 | ⊢ ( ( ♯ ‘ 𝐹 )  ∈  ℕ  ↔  ( ( ♯ ‘ 𝐹 )  ∈  ℕ0  ∧  ( ♯ ‘ 𝐹 )  ≠  0 ) ) | 
						
							| 17 | 10 15 16 | sylanbrc | ⊢ ( 𝐹  ∈  ( Word  ℝ  ∖  { ∅ } )  →  ( ♯ ‘ 𝐹 )  ∈  ℕ ) | 
						
							| 18 | 17 | adantr | ⊢ ( ( 𝐹  ∈  ( Word  ℝ  ∖  { ∅ } )  ∧  𝐾  ∈  ℝ )  →  ( ♯ ‘ 𝐹 )  ∈  ℕ ) | 
						
							| 19 |  | nnm1nn0 | ⊢ ( ( ♯ ‘ 𝐹 )  ∈  ℕ  →  ( ( ♯ ‘ 𝐹 )  −  1 )  ∈  ℕ0 ) | 
						
							| 20 | 18 19 | syl | ⊢ ( ( 𝐹  ∈  ( Word  ℝ  ∖  { ∅ } )  ∧  𝐾  ∈  ℝ )  →  ( ( ♯ ‘ 𝐹 )  −  1 )  ∈  ℕ0 ) | 
						
							| 21 |  | nn0uz | ⊢ ℕ0  =  ( ℤ≥ ‘ 0 ) | 
						
							| 22 | 20 21 | eleqtrdi | ⊢ ( ( 𝐹  ∈  ( Word  ℝ  ∖  { ∅ } )  ∧  𝐾  ∈  ℝ )  →  ( ( ♯ ‘ 𝐹 )  −  1 )  ∈  ( ℤ≥ ‘ 0 ) ) | 
						
							| 23 |  | ccatws1cl | ⊢ ( ( 𝐹  ∈  Word  ℝ  ∧  𝐾  ∈  ℝ )  →  ( 𝐹  ++  〈“ 𝐾 ”〉 )  ∈  Word  ℝ ) | 
						
							| 24 | 23 | adantr | ⊢ ( ( ( 𝐹  ∈  Word  ℝ  ∧  𝐾  ∈  ℝ )  ∧  𝑖  ∈  ( 0 ... ( ( ♯ ‘ 𝐹 )  −  1 ) ) )  →  ( 𝐹  ++  〈“ 𝐾 ”〉 )  ∈  Word  ℝ ) | 
						
							| 25 |  | wrdf | ⊢ ( ( 𝐹  ++  〈“ 𝐾 ”〉 )  ∈  Word  ℝ  →  ( 𝐹  ++  〈“ 𝐾 ”〉 ) : ( 0 ..^ ( ♯ ‘ ( 𝐹  ++  〈“ 𝐾 ”〉 ) ) ) ⟶ ℝ ) | 
						
							| 26 | 24 25 | syl | ⊢ ( ( ( 𝐹  ∈  Word  ℝ  ∧  𝐾  ∈  ℝ )  ∧  𝑖  ∈  ( 0 ... ( ( ♯ ‘ 𝐹 )  −  1 ) ) )  →  ( 𝐹  ++  〈“ 𝐾 ”〉 ) : ( 0 ..^ ( ♯ ‘ ( 𝐹  ++  〈“ 𝐾 ”〉 ) ) ) ⟶ ℝ ) | 
						
							| 27 | 9 | nn0zd | ⊢ ( 𝐹  ∈  Word  ℝ  →  ( ♯ ‘ 𝐹 )  ∈  ℤ ) | 
						
							| 28 |  | fzoval | ⊢ ( ( ♯ ‘ 𝐹 )  ∈  ℤ  →  ( 0 ..^ ( ♯ ‘ 𝐹 ) )  =  ( 0 ... ( ( ♯ ‘ 𝐹 )  −  1 ) ) ) | 
						
							| 29 | 27 28 | syl | ⊢ ( 𝐹  ∈  Word  ℝ  →  ( 0 ..^ ( ♯ ‘ 𝐹 ) )  =  ( 0 ... ( ( ♯ ‘ 𝐹 )  −  1 ) ) ) | 
						
							| 30 | 29 | adantr | ⊢ ( ( 𝐹  ∈  Word  ℝ  ∧  𝐾  ∈  ℝ )  →  ( 0 ..^ ( ♯ ‘ 𝐹 ) )  =  ( 0 ... ( ( ♯ ‘ 𝐹 )  −  1 ) ) ) | 
						
							| 31 |  | fzossfz | ⊢ ( 0 ..^ ( ♯ ‘ 𝐹 ) )  ⊆  ( 0 ... ( ♯ ‘ 𝐹 ) ) | 
						
							| 32 | 30 31 | eqsstrrdi | ⊢ ( ( 𝐹  ∈  Word  ℝ  ∧  𝐾  ∈  ℝ )  →  ( 0 ... ( ( ♯ ‘ 𝐹 )  −  1 ) )  ⊆  ( 0 ... ( ♯ ‘ 𝐹 ) ) ) | 
						
							| 33 |  | s1cl | ⊢ ( 𝐾  ∈  ℝ  →  〈“ 𝐾 ”〉  ∈  Word  ℝ ) | 
						
							| 34 |  | ccatlen | ⊢ ( ( 𝐹  ∈  Word  ℝ  ∧  〈“ 𝐾 ”〉  ∈  Word  ℝ )  →  ( ♯ ‘ ( 𝐹  ++  〈“ 𝐾 ”〉 ) )  =  ( ( ♯ ‘ 𝐹 )  +  ( ♯ ‘ 〈“ 𝐾 ”〉 ) ) ) | 
						
							| 35 | 33 34 | sylan2 | ⊢ ( ( 𝐹  ∈  Word  ℝ  ∧  𝐾  ∈  ℝ )  →  ( ♯ ‘ ( 𝐹  ++  〈“ 𝐾 ”〉 ) )  =  ( ( ♯ ‘ 𝐹 )  +  ( ♯ ‘ 〈“ 𝐾 ”〉 ) ) ) | 
						
							| 36 |  | s1len | ⊢ ( ♯ ‘ 〈“ 𝐾 ”〉 )  =  1 | 
						
							| 37 | 36 | oveq2i | ⊢ ( ( ♯ ‘ 𝐹 )  +  ( ♯ ‘ 〈“ 𝐾 ”〉 ) )  =  ( ( ♯ ‘ 𝐹 )  +  1 ) | 
						
							| 38 | 35 37 | eqtrdi | ⊢ ( ( 𝐹  ∈  Word  ℝ  ∧  𝐾  ∈  ℝ )  →  ( ♯ ‘ ( 𝐹  ++  〈“ 𝐾 ”〉 ) )  =  ( ( ♯ ‘ 𝐹 )  +  1 ) ) | 
						
							| 39 | 38 | oveq2d | ⊢ ( ( 𝐹  ∈  Word  ℝ  ∧  𝐾  ∈  ℝ )  →  ( 0 ..^ ( ♯ ‘ ( 𝐹  ++  〈“ 𝐾 ”〉 ) ) )  =  ( 0 ..^ ( ( ♯ ‘ 𝐹 )  +  1 ) ) ) | 
						
							| 40 | 27 | adantr | ⊢ ( ( 𝐹  ∈  Word  ℝ  ∧  𝐾  ∈  ℝ )  →  ( ♯ ‘ 𝐹 )  ∈  ℤ ) | 
						
							| 41 | 40 | peano2zd | ⊢ ( ( 𝐹  ∈  Word  ℝ  ∧  𝐾  ∈  ℝ )  →  ( ( ♯ ‘ 𝐹 )  +  1 )  ∈  ℤ ) | 
						
							| 42 |  | fzoval | ⊢ ( ( ( ♯ ‘ 𝐹 )  +  1 )  ∈  ℤ  →  ( 0 ..^ ( ( ♯ ‘ 𝐹 )  +  1 ) )  =  ( 0 ... ( ( ( ♯ ‘ 𝐹 )  +  1 )  −  1 ) ) ) | 
						
							| 43 | 41 42 | syl | ⊢ ( ( 𝐹  ∈  Word  ℝ  ∧  𝐾  ∈  ℝ )  →  ( 0 ..^ ( ( ♯ ‘ 𝐹 )  +  1 ) )  =  ( 0 ... ( ( ( ♯ ‘ 𝐹 )  +  1 )  −  1 ) ) ) | 
						
							| 44 | 9 | nn0cnd | ⊢ ( 𝐹  ∈  Word  ℝ  →  ( ♯ ‘ 𝐹 )  ∈  ℂ ) | 
						
							| 45 |  | 1cnd | ⊢ ( 𝐹  ∈  Word  ℝ  →  1  ∈  ℂ ) | 
						
							| 46 | 44 45 | pncand | ⊢ ( 𝐹  ∈  Word  ℝ  →  ( ( ( ♯ ‘ 𝐹 )  +  1 )  −  1 )  =  ( ♯ ‘ 𝐹 ) ) | 
						
							| 47 | 46 | adantr | ⊢ ( ( 𝐹  ∈  Word  ℝ  ∧  𝐾  ∈  ℝ )  →  ( ( ( ♯ ‘ 𝐹 )  +  1 )  −  1 )  =  ( ♯ ‘ 𝐹 ) ) | 
						
							| 48 | 47 | oveq2d | ⊢ ( ( 𝐹  ∈  Word  ℝ  ∧  𝐾  ∈  ℝ )  →  ( 0 ... ( ( ( ♯ ‘ 𝐹 )  +  1 )  −  1 ) )  =  ( 0 ... ( ♯ ‘ 𝐹 ) ) ) | 
						
							| 49 | 39 43 48 | 3eqtrd | ⊢ ( ( 𝐹  ∈  Word  ℝ  ∧  𝐾  ∈  ℝ )  →  ( 0 ..^ ( ♯ ‘ ( 𝐹  ++  〈“ 𝐾 ”〉 ) ) )  =  ( 0 ... ( ♯ ‘ 𝐹 ) ) ) | 
						
							| 50 | 32 49 | sseqtrrd | ⊢ ( ( 𝐹  ∈  Word  ℝ  ∧  𝐾  ∈  ℝ )  →  ( 0 ... ( ( ♯ ‘ 𝐹 )  −  1 ) )  ⊆  ( 0 ..^ ( ♯ ‘ ( 𝐹  ++  〈“ 𝐾 ”〉 ) ) ) ) | 
						
							| 51 | 50 | sselda | ⊢ ( ( ( 𝐹  ∈  Word  ℝ  ∧  𝐾  ∈  ℝ )  ∧  𝑖  ∈  ( 0 ... ( ( ♯ ‘ 𝐹 )  −  1 ) ) )  →  𝑖  ∈  ( 0 ..^ ( ♯ ‘ ( 𝐹  ++  〈“ 𝐾 ”〉 ) ) ) ) | 
						
							| 52 | 26 51 | ffvelcdmd | ⊢ ( ( ( 𝐹  ∈  Word  ℝ  ∧  𝐾  ∈  ℝ )  ∧  𝑖  ∈  ( 0 ... ( ( ♯ ‘ 𝐹 )  −  1 ) ) )  →  ( ( 𝐹  ++  〈“ 𝐾 ”〉 ) ‘ 𝑖 )  ∈  ℝ ) | 
						
							| 53 | 8 52 | sylanl1 | ⊢ ( ( ( 𝐹  ∈  ( Word  ℝ  ∖  { ∅ } )  ∧  𝐾  ∈  ℝ )  ∧  𝑖  ∈  ( 0 ... ( ( ♯ ‘ 𝐹 )  −  1 ) ) )  →  ( ( 𝐹  ++  〈“ 𝐾 ”〉 ) ‘ 𝑖 )  ∈  ℝ ) | 
						
							| 54 | 53 | rexrd | ⊢ ( ( ( 𝐹  ∈  ( Word  ℝ  ∖  { ∅ } )  ∧  𝐾  ∈  ℝ )  ∧  𝑖  ∈  ( 0 ... ( ( ♯ ‘ 𝐹 )  −  1 ) ) )  →  ( ( 𝐹  ++  〈“ 𝐾 ”〉 ) ‘ 𝑖 )  ∈  ℝ* ) | 
						
							| 55 |  | sgncl | ⊢ ( ( ( 𝐹  ++  〈“ 𝐾 ”〉 ) ‘ 𝑖 )  ∈  ℝ*  →  ( sgn ‘ ( ( 𝐹  ++  〈“ 𝐾 ”〉 ) ‘ 𝑖 ) )  ∈  { - 1 ,  0 ,  1 } ) | 
						
							| 56 | 54 55 | syl | ⊢ ( ( ( 𝐹  ∈  ( Word  ℝ  ∖  { ∅ } )  ∧  𝐾  ∈  ℝ )  ∧  𝑖  ∈  ( 0 ... ( ( ♯ ‘ 𝐹 )  −  1 ) ) )  →  ( sgn ‘ ( ( 𝐹  ++  〈“ 𝐾 ”〉 ) ‘ 𝑖 ) )  ∈  { - 1 ,  0 ,  1 } ) | 
						
							| 57 | 1 2 | signswplusg | ⊢  ⨣   =  ( +g ‘ 𝑊 ) | 
						
							| 58 |  | rexr | ⊢ ( 𝐾  ∈  ℝ  →  𝐾  ∈  ℝ* ) | 
						
							| 59 |  | sgncl | ⊢ ( 𝐾  ∈  ℝ*  →  ( sgn ‘ 𝐾 )  ∈  { - 1 ,  0 ,  1 } ) | 
						
							| 60 | 58 59 | syl | ⊢ ( 𝐾  ∈  ℝ  →  ( sgn ‘ 𝐾 )  ∈  { - 1 ,  0 ,  1 } ) | 
						
							| 61 | 60 | adantl | ⊢ ( ( 𝐹  ∈  ( Word  ℝ  ∖  { ∅ } )  ∧  𝐾  ∈  ℝ )  →  ( sgn ‘ 𝐾 )  ∈  { - 1 ,  0 ,  1 } ) | 
						
							| 62 |  | id | ⊢ ( 𝑖  =  ( ( ( ♯ ‘ 𝐹 )  −  1 )  +  1 )  →  𝑖  =  ( ( ( ♯ ‘ 𝐹 )  −  1 )  +  1 ) ) | 
						
							| 63 | 44 45 | npcand | ⊢ ( 𝐹  ∈  Word  ℝ  →  ( ( ( ♯ ‘ 𝐹 )  −  1 )  +  1 )  =  ( ♯ ‘ 𝐹 ) ) | 
						
							| 64 | 63 | adantr | ⊢ ( ( 𝐹  ∈  Word  ℝ  ∧  𝐾  ∈  ℝ )  →  ( ( ( ♯ ‘ 𝐹 )  −  1 )  +  1 )  =  ( ♯ ‘ 𝐹 ) ) | 
						
							| 65 | 62 64 | sylan9eqr | ⊢ ( ( ( 𝐹  ∈  Word  ℝ  ∧  𝐾  ∈  ℝ )  ∧  𝑖  =  ( ( ( ♯ ‘ 𝐹 )  −  1 )  +  1 ) )  →  𝑖  =  ( ♯ ‘ 𝐹 ) ) | 
						
							| 66 | 65 | fveq2d | ⊢ ( ( ( 𝐹  ∈  Word  ℝ  ∧  𝐾  ∈  ℝ )  ∧  𝑖  =  ( ( ( ♯ ‘ 𝐹 )  −  1 )  +  1 ) )  →  ( ( 𝐹  ++  〈“ 𝐾 ”〉 ) ‘ 𝑖 )  =  ( ( 𝐹  ++  〈“ 𝐾 ”〉 ) ‘ ( ♯ ‘ 𝐹 ) ) ) | 
						
							| 67 |  | ccatws1ls | ⊢ ( ( 𝐹  ∈  Word  ℝ  ∧  𝐾  ∈  ℝ )  →  ( ( 𝐹  ++  〈“ 𝐾 ”〉 ) ‘ ( ♯ ‘ 𝐹 ) )  =  𝐾 ) | 
						
							| 68 | 67 | adantr | ⊢ ( ( ( 𝐹  ∈  Word  ℝ  ∧  𝐾  ∈  ℝ )  ∧  𝑖  =  ( ( ( ♯ ‘ 𝐹 )  −  1 )  +  1 ) )  →  ( ( 𝐹  ++  〈“ 𝐾 ”〉 ) ‘ ( ♯ ‘ 𝐹 ) )  =  𝐾 ) | 
						
							| 69 | 66 68 | eqtrd | ⊢ ( ( ( 𝐹  ∈  Word  ℝ  ∧  𝐾  ∈  ℝ )  ∧  𝑖  =  ( ( ( ♯ ‘ 𝐹 )  −  1 )  +  1 ) )  →  ( ( 𝐹  ++  〈“ 𝐾 ”〉 ) ‘ 𝑖 )  =  𝐾 ) | 
						
							| 70 | 8 69 | sylanl1 | ⊢ ( ( ( 𝐹  ∈  ( Word  ℝ  ∖  { ∅ } )  ∧  𝐾  ∈  ℝ )  ∧  𝑖  =  ( ( ( ♯ ‘ 𝐹 )  −  1 )  +  1 ) )  →  ( ( 𝐹  ++  〈“ 𝐾 ”〉 ) ‘ 𝑖 )  =  𝐾 ) | 
						
							| 71 | 70 | fveq2d | ⊢ ( ( ( 𝐹  ∈  ( Word  ℝ  ∖  { ∅ } )  ∧  𝐾  ∈  ℝ )  ∧  𝑖  =  ( ( ( ♯ ‘ 𝐹 )  −  1 )  +  1 ) )  →  ( sgn ‘ ( ( 𝐹  ++  〈“ 𝐾 ”〉 ) ‘ 𝑖 ) )  =  ( sgn ‘ 𝐾 ) ) | 
						
							| 72 | 5 7 22 56 57 61 71 | gsumnunsn | ⊢ ( ( 𝐹  ∈  ( Word  ℝ  ∖  { ∅ } )  ∧  𝐾  ∈  ℝ )  →  ( 𝑊  Σg  ( 𝑖  ∈  ( 0 ... ( ( ( ♯ ‘ 𝐹 )  −  1 )  +  1 ) )  ↦  ( sgn ‘ ( ( 𝐹  ++  〈“ 𝐾 ”〉 ) ‘ 𝑖 ) ) ) )  =  ( ( 𝑊  Σg  ( 𝑖  ∈  ( 0 ... ( ( ♯ ‘ 𝐹 )  −  1 ) )  ↦  ( sgn ‘ ( ( 𝐹  ++  〈“ 𝐾 ”〉 ) ‘ 𝑖 ) ) ) )  ⨣  ( sgn ‘ 𝐾 ) ) ) | 
						
							| 73 | 8 63 | syl | ⊢ ( 𝐹  ∈  ( Word  ℝ  ∖  { ∅ } )  →  ( ( ( ♯ ‘ 𝐹 )  −  1 )  +  1 )  =  ( ♯ ‘ 𝐹 ) ) | 
						
							| 74 | 73 | adantr | ⊢ ( ( 𝐹  ∈  ( Word  ℝ  ∖  { ∅ } )  ∧  𝐾  ∈  ℝ )  →  ( ( ( ♯ ‘ 𝐹 )  −  1 )  +  1 )  =  ( ♯ ‘ 𝐹 ) ) | 
						
							| 75 | 74 | oveq2d | ⊢ ( ( 𝐹  ∈  ( Word  ℝ  ∖  { ∅ } )  ∧  𝐾  ∈  ℝ )  →  ( 0 ... ( ( ( ♯ ‘ 𝐹 )  −  1 )  +  1 ) )  =  ( 0 ... ( ♯ ‘ 𝐹 ) ) ) | 
						
							| 76 | 75 | mpteq1d | ⊢ ( ( 𝐹  ∈  ( Word  ℝ  ∖  { ∅ } )  ∧  𝐾  ∈  ℝ )  →  ( 𝑖  ∈  ( 0 ... ( ( ( ♯ ‘ 𝐹 )  −  1 )  +  1 ) )  ↦  ( sgn ‘ ( ( 𝐹  ++  〈“ 𝐾 ”〉 ) ‘ 𝑖 ) ) )  =  ( 𝑖  ∈  ( 0 ... ( ♯ ‘ 𝐹 ) )  ↦  ( sgn ‘ ( ( 𝐹  ++  〈“ 𝐾 ”〉 ) ‘ 𝑖 ) ) ) ) | 
						
							| 77 | 76 | oveq2d | ⊢ ( ( 𝐹  ∈  ( Word  ℝ  ∖  { ∅ } )  ∧  𝐾  ∈  ℝ )  →  ( 𝑊  Σg  ( 𝑖  ∈  ( 0 ... ( ( ( ♯ ‘ 𝐹 )  −  1 )  +  1 ) )  ↦  ( sgn ‘ ( ( 𝐹  ++  〈“ 𝐾 ”〉 ) ‘ 𝑖 ) ) ) )  =  ( 𝑊  Σg  ( 𝑖  ∈  ( 0 ... ( ♯ ‘ 𝐹 ) )  ↦  ( sgn ‘ ( ( 𝐹  ++  〈“ 𝐾 ”〉 ) ‘ 𝑖 ) ) ) ) ) | 
						
							| 78 |  | simpll | ⊢ ( ( ( 𝐹  ∈  Word  ℝ  ∧  𝐾  ∈  ℝ )  ∧  𝑖  ∈  ( 0 ... ( ( ♯ ‘ 𝐹 )  −  1 ) ) )  →  𝐹  ∈  Word  ℝ ) | 
						
							| 79 | 33 | ad2antlr | ⊢ ( ( ( 𝐹  ∈  Word  ℝ  ∧  𝐾  ∈  ℝ )  ∧  𝑖  ∈  ( 0 ... ( ( ♯ ‘ 𝐹 )  −  1 ) ) )  →  〈“ 𝐾 ”〉  ∈  Word  ℝ ) | 
						
							| 80 | 30 | eleq2d | ⊢ ( ( 𝐹  ∈  Word  ℝ  ∧  𝐾  ∈  ℝ )  →  ( 𝑖  ∈  ( 0 ..^ ( ♯ ‘ 𝐹 ) )  ↔  𝑖  ∈  ( 0 ... ( ( ♯ ‘ 𝐹 )  −  1 ) ) ) ) | 
						
							| 81 | 80 | biimpar | ⊢ ( ( ( 𝐹  ∈  Word  ℝ  ∧  𝐾  ∈  ℝ )  ∧  𝑖  ∈  ( 0 ... ( ( ♯ ‘ 𝐹 )  −  1 ) ) )  →  𝑖  ∈  ( 0 ..^ ( ♯ ‘ 𝐹 ) ) ) | 
						
							| 82 |  | ccatval1 | ⊢ ( ( 𝐹  ∈  Word  ℝ  ∧  〈“ 𝐾 ”〉  ∈  Word  ℝ  ∧  𝑖  ∈  ( 0 ..^ ( ♯ ‘ 𝐹 ) ) )  →  ( ( 𝐹  ++  〈“ 𝐾 ”〉 ) ‘ 𝑖 )  =  ( 𝐹 ‘ 𝑖 ) ) | 
						
							| 83 | 78 79 81 82 | syl3anc | ⊢ ( ( ( 𝐹  ∈  Word  ℝ  ∧  𝐾  ∈  ℝ )  ∧  𝑖  ∈  ( 0 ... ( ( ♯ ‘ 𝐹 )  −  1 ) ) )  →  ( ( 𝐹  ++  〈“ 𝐾 ”〉 ) ‘ 𝑖 )  =  ( 𝐹 ‘ 𝑖 ) ) | 
						
							| 84 | 83 | fveq2d | ⊢ ( ( ( 𝐹  ∈  Word  ℝ  ∧  𝐾  ∈  ℝ )  ∧  𝑖  ∈  ( 0 ... ( ( ♯ ‘ 𝐹 )  −  1 ) ) )  →  ( sgn ‘ ( ( 𝐹  ++  〈“ 𝐾 ”〉 ) ‘ 𝑖 ) )  =  ( sgn ‘ ( 𝐹 ‘ 𝑖 ) ) ) | 
						
							| 85 | 84 | mpteq2dva | ⊢ ( ( 𝐹  ∈  Word  ℝ  ∧  𝐾  ∈  ℝ )  →  ( 𝑖  ∈  ( 0 ... ( ( ♯ ‘ 𝐹 )  −  1 ) )  ↦  ( sgn ‘ ( ( 𝐹  ++  〈“ 𝐾 ”〉 ) ‘ 𝑖 ) ) )  =  ( 𝑖  ∈  ( 0 ... ( ( ♯ ‘ 𝐹 )  −  1 ) )  ↦  ( sgn ‘ ( 𝐹 ‘ 𝑖 ) ) ) ) | 
						
							| 86 | 8 85 | sylan | ⊢ ( ( 𝐹  ∈  ( Word  ℝ  ∖  { ∅ } )  ∧  𝐾  ∈  ℝ )  →  ( 𝑖  ∈  ( 0 ... ( ( ♯ ‘ 𝐹 )  −  1 ) )  ↦  ( sgn ‘ ( ( 𝐹  ++  〈“ 𝐾 ”〉 ) ‘ 𝑖 ) ) )  =  ( 𝑖  ∈  ( 0 ... ( ( ♯ ‘ 𝐹 )  −  1 ) )  ↦  ( sgn ‘ ( 𝐹 ‘ 𝑖 ) ) ) ) | 
						
							| 87 | 86 | oveq2d | ⊢ ( ( 𝐹  ∈  ( Word  ℝ  ∖  { ∅ } )  ∧  𝐾  ∈  ℝ )  →  ( 𝑊  Σg  ( 𝑖  ∈  ( 0 ... ( ( ♯ ‘ 𝐹 )  −  1 ) )  ↦  ( sgn ‘ ( ( 𝐹  ++  〈“ 𝐾 ”〉 ) ‘ 𝑖 ) ) ) )  =  ( 𝑊  Σg  ( 𝑖  ∈  ( 0 ... ( ( ♯ ‘ 𝐹 )  −  1 ) )  ↦  ( sgn ‘ ( 𝐹 ‘ 𝑖 ) ) ) ) ) | 
						
							| 88 | 87 | oveq1d | ⊢ ( ( 𝐹  ∈  ( Word  ℝ  ∖  { ∅ } )  ∧  𝐾  ∈  ℝ )  →  ( ( 𝑊  Σg  ( 𝑖  ∈  ( 0 ... ( ( ♯ ‘ 𝐹 )  −  1 ) )  ↦  ( sgn ‘ ( ( 𝐹  ++  〈“ 𝐾 ”〉 ) ‘ 𝑖 ) ) ) )  ⨣  ( sgn ‘ 𝐾 ) )  =  ( ( 𝑊  Σg  ( 𝑖  ∈  ( 0 ... ( ( ♯ ‘ 𝐹 )  −  1 ) )  ↦  ( sgn ‘ ( 𝐹 ‘ 𝑖 ) ) ) )  ⨣  ( sgn ‘ 𝐾 ) ) ) | 
						
							| 89 | 72 77 88 | 3eqtr3d | ⊢ ( ( 𝐹  ∈  ( Word  ℝ  ∖  { ∅ } )  ∧  𝐾  ∈  ℝ )  →  ( 𝑊  Σg  ( 𝑖  ∈  ( 0 ... ( ♯ ‘ 𝐹 ) )  ↦  ( sgn ‘ ( ( 𝐹  ++  〈“ 𝐾 ”〉 ) ‘ 𝑖 ) ) ) )  =  ( ( 𝑊  Σg  ( 𝑖  ∈  ( 0 ... ( ( ♯ ‘ 𝐹 )  −  1 ) )  ↦  ( sgn ‘ ( 𝐹 ‘ 𝑖 ) ) ) )  ⨣  ( sgn ‘ 𝐾 ) ) ) | 
						
							| 90 |  | eqid | ⊢ ( ♯ ‘ 𝐹 )  =  ( ♯ ‘ 𝐹 ) | 
						
							| 91 | 90 | olci | ⊢ ( ( ♯ ‘ 𝐹 )  ∈  ( 0 ..^ ( ♯ ‘ 𝐹 ) )  ∨  ( ♯ ‘ 𝐹 )  =  ( ♯ ‘ 𝐹 ) ) | 
						
							| 92 | 9 21 | eleqtrdi | ⊢ ( 𝐹  ∈  Word  ℝ  →  ( ♯ ‘ 𝐹 )  ∈  ( ℤ≥ ‘ 0 ) ) | 
						
							| 93 |  | fzosplitsni | ⊢ ( ( ♯ ‘ 𝐹 )  ∈  ( ℤ≥ ‘ 0 )  →  ( ( ♯ ‘ 𝐹 )  ∈  ( 0 ..^ ( ( ♯ ‘ 𝐹 )  +  1 ) )  ↔  ( ( ♯ ‘ 𝐹 )  ∈  ( 0 ..^ ( ♯ ‘ 𝐹 ) )  ∨  ( ♯ ‘ 𝐹 )  =  ( ♯ ‘ 𝐹 ) ) ) ) | 
						
							| 94 | 92 93 | syl | ⊢ ( 𝐹  ∈  Word  ℝ  →  ( ( ♯ ‘ 𝐹 )  ∈  ( 0 ..^ ( ( ♯ ‘ 𝐹 )  +  1 ) )  ↔  ( ( ♯ ‘ 𝐹 )  ∈  ( 0 ..^ ( ♯ ‘ 𝐹 ) )  ∨  ( ♯ ‘ 𝐹 )  =  ( ♯ ‘ 𝐹 ) ) ) ) | 
						
							| 95 | 91 94 | mpbiri | ⊢ ( 𝐹  ∈  Word  ℝ  →  ( ♯ ‘ 𝐹 )  ∈  ( 0 ..^ ( ( ♯ ‘ 𝐹 )  +  1 ) ) ) | 
						
							| 96 | 95 | adantr | ⊢ ( ( 𝐹  ∈  Word  ℝ  ∧  𝐾  ∈  ℝ )  →  ( ♯ ‘ 𝐹 )  ∈  ( 0 ..^ ( ( ♯ ‘ 𝐹 )  +  1 ) ) ) | 
						
							| 97 | 96 39 | eleqtrrd | ⊢ ( ( 𝐹  ∈  Word  ℝ  ∧  𝐾  ∈  ℝ )  →  ( ♯ ‘ 𝐹 )  ∈  ( 0 ..^ ( ♯ ‘ ( 𝐹  ++  〈“ 𝐾 ”〉 ) ) ) ) | 
						
							| 98 | 1 2 3 4 | signstfval | ⊢ ( ( ( 𝐹  ++  〈“ 𝐾 ”〉 )  ∈  Word  ℝ  ∧  ( ♯ ‘ 𝐹 )  ∈  ( 0 ..^ ( ♯ ‘ ( 𝐹  ++  〈“ 𝐾 ”〉 ) ) ) )  →  ( ( 𝑇 ‘ ( 𝐹  ++  〈“ 𝐾 ”〉 ) ) ‘ ( ♯ ‘ 𝐹 ) )  =  ( 𝑊  Σg  ( 𝑖  ∈  ( 0 ... ( ♯ ‘ 𝐹 ) )  ↦  ( sgn ‘ ( ( 𝐹  ++  〈“ 𝐾 ”〉 ) ‘ 𝑖 ) ) ) ) ) | 
						
							| 99 | 23 97 98 | syl2anc | ⊢ ( ( 𝐹  ∈  Word  ℝ  ∧  𝐾  ∈  ℝ )  →  ( ( 𝑇 ‘ ( 𝐹  ++  〈“ 𝐾 ”〉 ) ) ‘ ( ♯ ‘ 𝐹 ) )  =  ( 𝑊  Σg  ( 𝑖  ∈  ( 0 ... ( ♯ ‘ 𝐹 ) )  ↦  ( sgn ‘ ( ( 𝐹  ++  〈“ 𝐾 ”〉 ) ‘ 𝑖 ) ) ) ) ) | 
						
							| 100 | 8 99 | sylan | ⊢ ( ( 𝐹  ∈  ( Word  ℝ  ∖  { ∅ } )  ∧  𝐾  ∈  ℝ )  →  ( ( 𝑇 ‘ ( 𝐹  ++  〈“ 𝐾 ”〉 ) ) ‘ ( ♯ ‘ 𝐹 ) )  =  ( 𝑊  Σg  ( 𝑖  ∈  ( 0 ... ( ♯ ‘ 𝐹 ) )  ↦  ( sgn ‘ ( ( 𝐹  ++  〈“ 𝐾 ”〉 ) ‘ 𝑖 ) ) ) ) ) | 
						
							| 101 |  | fzo0end | ⊢ ( ( ♯ ‘ 𝐹 )  ∈  ℕ  →  ( ( ♯ ‘ 𝐹 )  −  1 )  ∈  ( 0 ..^ ( ♯ ‘ 𝐹 ) ) ) | 
						
							| 102 | 17 101 | syl | ⊢ ( 𝐹  ∈  ( Word  ℝ  ∖  { ∅ } )  →  ( ( ♯ ‘ 𝐹 )  −  1 )  ∈  ( 0 ..^ ( ♯ ‘ 𝐹 ) ) ) | 
						
							| 103 | 1 2 3 4 | signstfval | ⊢ ( ( 𝐹  ∈  Word  ℝ  ∧  ( ( ♯ ‘ 𝐹 )  −  1 )  ∈  ( 0 ..^ ( ♯ ‘ 𝐹 ) ) )  →  ( ( 𝑇 ‘ 𝐹 ) ‘ ( ( ♯ ‘ 𝐹 )  −  1 ) )  =  ( 𝑊  Σg  ( 𝑖  ∈  ( 0 ... ( ( ♯ ‘ 𝐹 )  −  1 ) )  ↦  ( sgn ‘ ( 𝐹 ‘ 𝑖 ) ) ) ) ) | 
						
							| 104 | 8 102 103 | syl2anc | ⊢ ( 𝐹  ∈  ( Word  ℝ  ∖  { ∅ } )  →  ( ( 𝑇 ‘ 𝐹 ) ‘ ( ( ♯ ‘ 𝐹 )  −  1 ) )  =  ( 𝑊  Σg  ( 𝑖  ∈  ( 0 ... ( ( ♯ ‘ 𝐹 )  −  1 ) )  ↦  ( sgn ‘ ( 𝐹 ‘ 𝑖 ) ) ) ) ) | 
						
							| 105 | 104 | adantr | ⊢ ( ( 𝐹  ∈  ( Word  ℝ  ∖  { ∅ } )  ∧  𝐾  ∈  ℝ )  →  ( ( 𝑇 ‘ 𝐹 ) ‘ ( ( ♯ ‘ 𝐹 )  −  1 ) )  =  ( 𝑊  Σg  ( 𝑖  ∈  ( 0 ... ( ( ♯ ‘ 𝐹 )  −  1 ) )  ↦  ( sgn ‘ ( 𝐹 ‘ 𝑖 ) ) ) ) ) | 
						
							| 106 | 105 | oveq1d | ⊢ ( ( 𝐹  ∈  ( Word  ℝ  ∖  { ∅ } )  ∧  𝐾  ∈  ℝ )  →  ( ( ( 𝑇 ‘ 𝐹 ) ‘ ( ( ♯ ‘ 𝐹 )  −  1 ) )  ⨣  ( sgn ‘ 𝐾 ) )  =  ( ( 𝑊  Σg  ( 𝑖  ∈  ( 0 ... ( ( ♯ ‘ 𝐹 )  −  1 ) )  ↦  ( sgn ‘ ( 𝐹 ‘ 𝑖 ) ) ) )  ⨣  ( sgn ‘ 𝐾 ) ) ) | 
						
							| 107 | 89 100 106 | 3eqtr4d | ⊢ ( ( 𝐹  ∈  ( Word  ℝ  ∖  { ∅ } )  ∧  𝐾  ∈  ℝ )  →  ( ( 𝑇 ‘ ( 𝐹  ++  〈“ 𝐾 ”〉 ) ) ‘ ( ♯ ‘ 𝐹 ) )  =  ( ( ( 𝑇 ‘ 𝐹 ) ‘ ( ( ♯ ‘ 𝐹 )  −  1 ) )  ⨣  ( sgn ‘ 𝐾 ) ) ) |