| Step | Hyp | Ref | Expression | 
						
							| 1 |  | efgval.w | ⊢ 𝑊  =  (  I  ‘ Word  ( 𝐼  ×  2o ) ) | 
						
							| 2 |  | efgval.r | ⊢  ∼   =  (  ~FG  ‘ 𝐼 ) | 
						
							| 3 |  | efgval2.m | ⊢ 𝑀  =  ( 𝑦  ∈  𝐼 ,  𝑧  ∈  2o  ↦  〈 𝑦 ,  ( 1o  ∖  𝑧 ) 〉 ) | 
						
							| 4 |  | efgval2.t | ⊢ 𝑇  =  ( 𝑣  ∈  𝑊  ↦  ( 𝑛  ∈  ( 0 ... ( ♯ ‘ 𝑣 ) ) ,  𝑤  ∈  ( 𝐼  ×  2o )  ↦  ( 𝑣  splice  〈 𝑛 ,  𝑛 ,  〈“ 𝑤 ( 𝑀 ‘ 𝑤 ) ”〉 〉 ) ) ) | 
						
							| 5 |  | efgred.d | ⊢ 𝐷  =  ( 𝑊  ∖  ∪  𝑥  ∈  𝑊 ran  ( 𝑇 ‘ 𝑥 ) ) | 
						
							| 6 |  | efgred.s | ⊢ 𝑆  =  ( 𝑚  ∈  { 𝑡  ∈  ( Word  𝑊  ∖  { ∅ } )  ∣  ( ( 𝑡 ‘ 0 )  ∈  𝐷  ∧  ∀ 𝑘  ∈  ( 1 ..^ ( ♯ ‘ 𝑡 ) ) ( 𝑡 ‘ 𝑘 )  ∈  ran  ( 𝑇 ‘ ( 𝑡 ‘ ( 𝑘  −  1 ) ) ) ) }  ↦  ( 𝑚 ‘ ( ( ♯ ‘ 𝑚 )  −  1 ) ) ) | 
						
							| 7 | 1 2 3 4 5 6 | efgsval | ⊢ ( 𝐹  ∈  dom  𝑆  →  ( 𝑆 ‘ 𝐹 )  =  ( 𝐹 ‘ ( ( ♯ ‘ 𝐹 )  −  1 ) ) ) | 
						
							| 8 | 7 | adantr | ⊢ ( ( 𝐹  ∈  dom  𝑆  ∧  ( ( ♯ ‘ 𝐹 )  −  1 )  ∈  ℕ )  →  ( 𝑆 ‘ 𝐹 )  =  ( 𝐹 ‘ ( ( ♯ ‘ 𝐹 )  −  1 ) ) ) | 
						
							| 9 |  | fveq2 | ⊢ ( 𝑖  =  ( ( ♯ ‘ 𝐹 )  −  1 )  →  ( 𝐹 ‘ 𝑖 )  =  ( 𝐹 ‘ ( ( ♯ ‘ 𝐹 )  −  1 ) ) ) | 
						
							| 10 |  | fvoveq1 | ⊢ ( 𝑖  =  ( ( ♯ ‘ 𝐹 )  −  1 )  →  ( 𝐹 ‘ ( 𝑖  −  1 ) )  =  ( 𝐹 ‘ ( ( ( ♯ ‘ 𝐹 )  −  1 )  −  1 ) ) ) | 
						
							| 11 | 10 | fveq2d | ⊢ ( 𝑖  =  ( ( ♯ ‘ 𝐹 )  −  1 )  →  ( 𝑇 ‘ ( 𝐹 ‘ ( 𝑖  −  1 ) ) )  =  ( 𝑇 ‘ ( 𝐹 ‘ ( ( ( ♯ ‘ 𝐹 )  −  1 )  −  1 ) ) ) ) | 
						
							| 12 | 11 | rneqd | ⊢ ( 𝑖  =  ( ( ♯ ‘ 𝐹 )  −  1 )  →  ran  ( 𝑇 ‘ ( 𝐹 ‘ ( 𝑖  −  1 ) ) )  =  ran  ( 𝑇 ‘ ( 𝐹 ‘ ( ( ( ♯ ‘ 𝐹 )  −  1 )  −  1 ) ) ) ) | 
						
							| 13 | 9 12 | eleq12d | ⊢ ( 𝑖  =  ( ( ♯ ‘ 𝐹 )  −  1 )  →  ( ( 𝐹 ‘ 𝑖 )  ∈  ran  ( 𝑇 ‘ ( 𝐹 ‘ ( 𝑖  −  1 ) ) )  ↔  ( 𝐹 ‘ ( ( ♯ ‘ 𝐹 )  −  1 ) )  ∈  ran  ( 𝑇 ‘ ( 𝐹 ‘ ( ( ( ♯ ‘ 𝐹 )  −  1 )  −  1 ) ) ) ) ) | 
						
							| 14 | 1 2 3 4 5 6 | efgsdm | ⊢ ( 𝐹  ∈  dom  𝑆  ↔  ( 𝐹  ∈  ( Word  𝑊  ∖  { ∅ } )  ∧  ( 𝐹 ‘ 0 )  ∈  𝐷  ∧  ∀ 𝑖  ∈  ( 1 ..^ ( ♯ ‘ 𝐹 ) ) ( 𝐹 ‘ 𝑖 )  ∈  ran  ( 𝑇 ‘ ( 𝐹 ‘ ( 𝑖  −  1 ) ) ) ) ) | 
						
							| 15 | 14 | simp3bi | ⊢ ( 𝐹  ∈  dom  𝑆  →  ∀ 𝑖  ∈  ( 1 ..^ ( ♯ ‘ 𝐹 ) ) ( 𝐹 ‘ 𝑖 )  ∈  ran  ( 𝑇 ‘ ( 𝐹 ‘ ( 𝑖  −  1 ) ) ) ) | 
						
							| 16 | 15 | adantr | ⊢ ( ( 𝐹  ∈  dom  𝑆  ∧  ( ( ♯ ‘ 𝐹 )  −  1 )  ∈  ℕ )  →  ∀ 𝑖  ∈  ( 1 ..^ ( ♯ ‘ 𝐹 ) ) ( 𝐹 ‘ 𝑖 )  ∈  ran  ( 𝑇 ‘ ( 𝐹 ‘ ( 𝑖  −  1 ) ) ) ) | 
						
							| 17 |  | simpr | ⊢ ( ( 𝐹  ∈  dom  𝑆  ∧  ( ( ♯ ‘ 𝐹 )  −  1 )  ∈  ℕ )  →  ( ( ♯ ‘ 𝐹 )  −  1 )  ∈  ℕ ) | 
						
							| 18 |  | nnuz | ⊢ ℕ  =  ( ℤ≥ ‘ 1 ) | 
						
							| 19 | 17 18 | eleqtrdi | ⊢ ( ( 𝐹  ∈  dom  𝑆  ∧  ( ( ♯ ‘ 𝐹 )  −  1 )  ∈  ℕ )  →  ( ( ♯ ‘ 𝐹 )  −  1 )  ∈  ( ℤ≥ ‘ 1 ) ) | 
						
							| 20 |  | eluzfz1 | ⊢ ( ( ( ♯ ‘ 𝐹 )  −  1 )  ∈  ( ℤ≥ ‘ 1 )  →  1  ∈  ( 1 ... ( ( ♯ ‘ 𝐹 )  −  1 ) ) ) | 
						
							| 21 | 19 20 | syl | ⊢ ( ( 𝐹  ∈  dom  𝑆  ∧  ( ( ♯ ‘ 𝐹 )  −  1 )  ∈  ℕ )  →  1  ∈  ( 1 ... ( ( ♯ ‘ 𝐹 )  −  1 ) ) ) | 
						
							| 22 | 14 | simp1bi | ⊢ ( 𝐹  ∈  dom  𝑆  →  𝐹  ∈  ( Word  𝑊  ∖  { ∅ } ) ) | 
						
							| 23 | 22 | adantr | ⊢ ( ( 𝐹  ∈  dom  𝑆  ∧  ( ( ♯ ‘ 𝐹 )  −  1 )  ∈  ℕ )  →  𝐹  ∈  ( Word  𝑊  ∖  { ∅ } ) ) | 
						
							| 24 | 23 | eldifad | ⊢ ( ( 𝐹  ∈  dom  𝑆  ∧  ( ( ♯ ‘ 𝐹 )  −  1 )  ∈  ℕ )  →  𝐹  ∈  Word  𝑊 ) | 
						
							| 25 |  | lencl | ⊢ ( 𝐹  ∈  Word  𝑊  →  ( ♯ ‘ 𝐹 )  ∈  ℕ0 ) | 
						
							| 26 |  | nn0z | ⊢ ( ( ♯ ‘ 𝐹 )  ∈  ℕ0  →  ( ♯ ‘ 𝐹 )  ∈  ℤ ) | 
						
							| 27 |  | fzoval | ⊢ ( ( ♯ ‘ 𝐹 )  ∈  ℤ  →  ( 1 ..^ ( ♯ ‘ 𝐹 ) )  =  ( 1 ... ( ( ♯ ‘ 𝐹 )  −  1 ) ) ) | 
						
							| 28 | 24 25 26 27 | 4syl | ⊢ ( ( 𝐹  ∈  dom  𝑆  ∧  ( ( ♯ ‘ 𝐹 )  −  1 )  ∈  ℕ )  →  ( 1 ..^ ( ♯ ‘ 𝐹 ) )  =  ( 1 ... ( ( ♯ ‘ 𝐹 )  −  1 ) ) ) | 
						
							| 29 | 21 28 | eleqtrrd | ⊢ ( ( 𝐹  ∈  dom  𝑆  ∧  ( ( ♯ ‘ 𝐹 )  −  1 )  ∈  ℕ )  →  1  ∈  ( 1 ..^ ( ♯ ‘ 𝐹 ) ) ) | 
						
							| 30 |  | fzoend | ⊢ ( 1  ∈  ( 1 ..^ ( ♯ ‘ 𝐹 ) )  →  ( ( ♯ ‘ 𝐹 )  −  1 )  ∈  ( 1 ..^ ( ♯ ‘ 𝐹 ) ) ) | 
						
							| 31 | 29 30 | syl | ⊢ ( ( 𝐹  ∈  dom  𝑆  ∧  ( ( ♯ ‘ 𝐹 )  −  1 )  ∈  ℕ )  →  ( ( ♯ ‘ 𝐹 )  −  1 )  ∈  ( 1 ..^ ( ♯ ‘ 𝐹 ) ) ) | 
						
							| 32 | 13 16 31 | rspcdva | ⊢ ( ( 𝐹  ∈  dom  𝑆  ∧  ( ( ♯ ‘ 𝐹 )  −  1 )  ∈  ℕ )  →  ( 𝐹 ‘ ( ( ♯ ‘ 𝐹 )  −  1 ) )  ∈  ran  ( 𝑇 ‘ ( 𝐹 ‘ ( ( ( ♯ ‘ 𝐹 )  −  1 )  −  1 ) ) ) ) | 
						
							| 33 | 8 32 | eqeltrd | ⊢ ( ( 𝐹  ∈  dom  𝑆  ∧  ( ( ♯ ‘ 𝐹 )  −  1 )  ∈  ℕ )  →  ( 𝑆 ‘ 𝐹 )  ∈  ran  ( 𝑇 ‘ ( 𝐹 ‘ ( ( ( ♯ ‘ 𝐹 )  −  1 )  −  1 ) ) ) ) |