| Step | Hyp | Ref | Expression | 
						
							| 1 |  | seqf1o.1 | ⊢ ( ( 𝜑  ∧  ( 𝑥  ∈  𝑆  ∧  𝑦  ∈  𝑆 ) )  →  ( 𝑥  +  𝑦 )  ∈  𝑆 ) | 
						
							| 2 |  | seqf1o.2 | ⊢ ( ( 𝜑  ∧  ( 𝑥  ∈  𝐶  ∧  𝑦  ∈  𝐶 ) )  →  ( 𝑥  +  𝑦 )  =  ( 𝑦  +  𝑥 ) ) | 
						
							| 3 |  | seqf1o.3 | ⊢ ( ( 𝜑  ∧  ( 𝑥  ∈  𝑆  ∧  𝑦  ∈  𝑆  ∧  𝑧  ∈  𝑆 ) )  →  ( ( 𝑥  +  𝑦 )  +  𝑧 )  =  ( 𝑥  +  ( 𝑦  +  𝑧 ) ) ) | 
						
							| 4 |  | seqf1o.4 | ⊢ ( 𝜑  →  𝑁  ∈  ( ℤ≥ ‘ 𝑀 ) ) | 
						
							| 5 |  | seqf1o.5 | ⊢ ( 𝜑  →  𝐶  ⊆  𝑆 ) | 
						
							| 6 |  | seqf1olem.5 | ⊢ ( 𝜑  →  𝐹 : ( 𝑀 ... ( 𝑁  +  1 ) ) –1-1-onto→ ( 𝑀 ... ( 𝑁  +  1 ) ) ) | 
						
							| 7 |  | seqf1olem.6 | ⊢ ( 𝜑  →  𝐺 : ( 𝑀 ... ( 𝑁  +  1 ) ) ⟶ 𝐶 ) | 
						
							| 8 |  | seqf1olem.7 | ⊢ 𝐽  =  ( 𝑘  ∈  ( 𝑀 ... 𝑁 )  ↦  ( 𝐹 ‘ if ( 𝑘  <  𝐾 ,  𝑘 ,  ( 𝑘  +  1 ) ) ) ) | 
						
							| 9 |  | seqf1olem.8 | ⊢ 𝐾  =  ( ◡ 𝐹 ‘ ( 𝑁  +  1 ) ) | 
						
							| 10 |  | fvexd | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  →  ( 𝐹 ‘ if ( 𝑘  <  𝐾 ,  𝑘 ,  ( 𝑘  +  1 ) ) )  ∈  V ) | 
						
							| 11 |  | fvex | ⊢ ( ◡ 𝐹 ‘ 𝑥 )  ∈  V | 
						
							| 12 |  | ovex | ⊢ ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 )  ∈  V | 
						
							| 13 | 11 12 | ifex | ⊢ if ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾 ,  ( ◡ 𝐹 ‘ 𝑥 ) ,  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) )  ∈  V | 
						
							| 14 | 13 | a1i | ⊢ ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  →  if ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾 ,  ( ◡ 𝐹 ‘ 𝑥 ) ,  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) )  ∈  V ) | 
						
							| 15 |  | iftrue | ⊢ ( 𝑘  <  𝐾  →  if ( 𝑘  <  𝐾 ,  𝑘 ,  ( 𝑘  +  1 ) )  =  𝑘 ) | 
						
							| 16 | 15 | fveq2d | ⊢ ( 𝑘  <  𝐾  →  ( 𝐹 ‘ if ( 𝑘  <  𝐾 ,  𝑘 ,  ( 𝑘  +  1 ) ) )  =  ( 𝐹 ‘ 𝑘 ) ) | 
						
							| 17 | 16 | eqeq2d | ⊢ ( 𝑘  <  𝐾  →  ( 𝑥  =  ( 𝐹 ‘ if ( 𝑘  <  𝐾 ,  𝑘 ,  ( 𝑘  +  1 ) ) )  ↔  𝑥  =  ( 𝐹 ‘ 𝑘 ) ) ) | 
						
							| 18 | 17 | adantl | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  𝑘  <  𝐾 )  →  ( 𝑥  =  ( 𝐹 ‘ if ( 𝑘  <  𝐾 ,  𝑘 ,  ( 𝑘  +  1 ) ) )  ↔  𝑥  =  ( 𝐹 ‘ 𝑘 ) ) ) | 
						
							| 19 |  | simprr | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( 𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ 𝑘 ) ) )  →  𝑥  =  ( 𝐹 ‘ 𝑘 ) ) | 
						
							| 20 |  | elfzelz | ⊢ ( 𝑘  ∈  ( 𝑀 ... 𝑁 )  →  𝑘  ∈  ℤ ) | 
						
							| 21 | 20 | zred | ⊢ ( 𝑘  ∈  ( 𝑀 ... 𝑁 )  →  𝑘  ∈  ℝ ) | 
						
							| 22 | 21 | ad2antlr | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( 𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ 𝑘 ) ) )  →  𝑘  ∈  ℝ ) | 
						
							| 23 |  | simprl | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( 𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ 𝑘 ) ) )  →  𝑘  <  𝐾 ) | 
						
							| 24 | 22 23 | gtned | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( 𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ 𝑘 ) ) )  →  𝐾  ≠  𝑘 ) | 
						
							| 25 |  | f1of | ⊢ ( 𝐹 : ( 𝑀 ... ( 𝑁  +  1 ) ) –1-1-onto→ ( 𝑀 ... ( 𝑁  +  1 ) )  →  𝐹 : ( 𝑀 ... ( 𝑁  +  1 ) ) ⟶ ( 𝑀 ... ( 𝑁  +  1 ) ) ) | 
						
							| 26 | 6 25 | syl | ⊢ ( 𝜑  →  𝐹 : ( 𝑀 ... ( 𝑁  +  1 ) ) ⟶ ( 𝑀 ... ( 𝑁  +  1 ) ) ) | 
						
							| 27 | 26 | ad2antrr | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( 𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ 𝑘 ) ) )  →  𝐹 : ( 𝑀 ... ( 𝑁  +  1 ) ) ⟶ ( 𝑀 ... ( 𝑁  +  1 ) ) ) | 
						
							| 28 |  | fzssp1 | ⊢ ( 𝑀 ... 𝑁 )  ⊆  ( 𝑀 ... ( 𝑁  +  1 ) ) | 
						
							| 29 |  | simplr | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( 𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ 𝑘 ) ) )  →  𝑘  ∈  ( 𝑀 ... 𝑁 ) ) | 
						
							| 30 | 28 29 | sselid | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( 𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ 𝑘 ) ) )  →  𝑘  ∈  ( 𝑀 ... ( 𝑁  +  1 ) ) ) | 
						
							| 31 | 27 30 | ffvelcdmd | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( 𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ 𝑘 ) ) )  →  ( 𝐹 ‘ 𝑘 )  ∈  ( 𝑀 ... ( 𝑁  +  1 ) ) ) | 
						
							| 32 |  | elfzp1 | ⊢ ( 𝑁  ∈  ( ℤ≥ ‘ 𝑀 )  →  ( ( 𝐹 ‘ 𝑘 )  ∈  ( 𝑀 ... ( 𝑁  +  1 ) )  ↔  ( ( 𝐹 ‘ 𝑘 )  ∈  ( 𝑀 ... 𝑁 )  ∨  ( 𝐹 ‘ 𝑘 )  =  ( 𝑁  +  1 ) ) ) ) | 
						
							| 33 | 4 32 | syl | ⊢ ( 𝜑  →  ( ( 𝐹 ‘ 𝑘 )  ∈  ( 𝑀 ... ( 𝑁  +  1 ) )  ↔  ( ( 𝐹 ‘ 𝑘 )  ∈  ( 𝑀 ... 𝑁 )  ∨  ( 𝐹 ‘ 𝑘 )  =  ( 𝑁  +  1 ) ) ) ) | 
						
							| 34 | 33 | ad2antrr | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( 𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ 𝑘 ) ) )  →  ( ( 𝐹 ‘ 𝑘 )  ∈  ( 𝑀 ... ( 𝑁  +  1 ) )  ↔  ( ( 𝐹 ‘ 𝑘 )  ∈  ( 𝑀 ... 𝑁 )  ∨  ( 𝐹 ‘ 𝑘 )  =  ( 𝑁  +  1 ) ) ) ) | 
						
							| 35 | 31 34 | mpbid | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( 𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ 𝑘 ) ) )  →  ( ( 𝐹 ‘ 𝑘 )  ∈  ( 𝑀 ... 𝑁 )  ∨  ( 𝐹 ‘ 𝑘 )  =  ( 𝑁  +  1 ) ) ) | 
						
							| 36 | 35 | ord | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( 𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ 𝑘 ) ) )  →  ( ¬  ( 𝐹 ‘ 𝑘 )  ∈  ( 𝑀 ... 𝑁 )  →  ( 𝐹 ‘ 𝑘 )  =  ( 𝑁  +  1 ) ) ) | 
						
							| 37 | 6 | ad2antrr | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( 𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ 𝑘 ) ) )  →  𝐹 : ( 𝑀 ... ( 𝑁  +  1 ) ) –1-1-onto→ ( 𝑀 ... ( 𝑁  +  1 ) ) ) | 
						
							| 38 |  | f1ocnvfv | ⊢ ( ( 𝐹 : ( 𝑀 ... ( 𝑁  +  1 ) ) –1-1-onto→ ( 𝑀 ... ( 𝑁  +  1 ) )  ∧  𝑘  ∈  ( 𝑀 ... ( 𝑁  +  1 ) ) )  →  ( ( 𝐹 ‘ 𝑘 )  =  ( 𝑁  +  1 )  →  ( ◡ 𝐹 ‘ ( 𝑁  +  1 ) )  =  𝑘 ) ) | 
						
							| 39 | 37 30 38 | syl2anc | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( 𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ 𝑘 ) ) )  →  ( ( 𝐹 ‘ 𝑘 )  =  ( 𝑁  +  1 )  →  ( ◡ 𝐹 ‘ ( 𝑁  +  1 ) )  =  𝑘 ) ) | 
						
							| 40 | 9 | eqeq1i | ⊢ ( 𝐾  =  𝑘  ↔  ( ◡ 𝐹 ‘ ( 𝑁  +  1 ) )  =  𝑘 ) | 
						
							| 41 | 39 40 | imbitrrdi | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( 𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ 𝑘 ) ) )  →  ( ( 𝐹 ‘ 𝑘 )  =  ( 𝑁  +  1 )  →  𝐾  =  𝑘 ) ) | 
						
							| 42 | 36 41 | syld | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( 𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ 𝑘 ) ) )  →  ( ¬  ( 𝐹 ‘ 𝑘 )  ∈  ( 𝑀 ... 𝑁 )  →  𝐾  =  𝑘 ) ) | 
						
							| 43 | 42 | necon1ad | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( 𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ 𝑘 ) ) )  →  ( 𝐾  ≠  𝑘  →  ( 𝐹 ‘ 𝑘 )  ∈  ( 𝑀 ... 𝑁 ) ) ) | 
						
							| 44 | 24 43 | mpd | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( 𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ 𝑘 ) ) )  →  ( 𝐹 ‘ 𝑘 )  ∈  ( 𝑀 ... 𝑁 ) ) | 
						
							| 45 | 19 44 | eqeltrd | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( 𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ 𝑘 ) ) )  →  𝑥  ∈  ( 𝑀 ... 𝑁 ) ) | 
						
							| 46 | 19 | eqcomd | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( 𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ 𝑘 ) ) )  →  ( 𝐹 ‘ 𝑘 )  =  𝑥 ) | 
						
							| 47 |  | f1ocnvfv | ⊢ ( ( 𝐹 : ( 𝑀 ... ( 𝑁  +  1 ) ) –1-1-onto→ ( 𝑀 ... ( 𝑁  +  1 ) )  ∧  𝑘  ∈  ( 𝑀 ... ( 𝑁  +  1 ) ) )  →  ( ( 𝐹 ‘ 𝑘 )  =  𝑥  →  ( ◡ 𝐹 ‘ 𝑥 )  =  𝑘 ) ) | 
						
							| 48 | 37 30 47 | syl2anc | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( 𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ 𝑘 ) ) )  →  ( ( 𝐹 ‘ 𝑘 )  =  𝑥  →  ( ◡ 𝐹 ‘ 𝑥 )  =  𝑘 ) ) | 
						
							| 49 | 46 48 | mpd | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( 𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ 𝑘 ) ) )  →  ( ◡ 𝐹 ‘ 𝑥 )  =  𝑘 ) | 
						
							| 50 | 49 23 | eqbrtrd | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( 𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ 𝑘 ) ) )  →  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾 ) | 
						
							| 51 |  | iftrue | ⊢ ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  →  if ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾 ,  ( ◡ 𝐹 ‘ 𝑥 ) ,  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) )  =  ( ◡ 𝐹 ‘ 𝑥 ) ) | 
						
							| 52 | 50 51 | syl | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( 𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ 𝑘 ) ) )  →  if ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾 ,  ( ◡ 𝐹 ‘ 𝑥 ) ,  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) )  =  ( ◡ 𝐹 ‘ 𝑥 ) ) | 
						
							| 53 | 52 49 | eqtr2d | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( 𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ 𝑘 ) ) )  →  𝑘  =  if ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾 ,  ( ◡ 𝐹 ‘ 𝑥 ) ,  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) ) | 
						
							| 54 | 45 53 | jca | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( 𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ 𝑘 ) ) )  →  ( 𝑥  ∈  ( 𝑀 ... 𝑁 )  ∧  𝑘  =  if ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾 ,  ( ◡ 𝐹 ‘ 𝑥 ) ,  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) ) ) | 
						
							| 55 | 54 | expr | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  𝑘  <  𝐾 )  →  ( 𝑥  =  ( 𝐹 ‘ 𝑘 )  →  ( 𝑥  ∈  ( 𝑀 ... 𝑁 )  ∧  𝑘  =  if ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾 ,  ( ◡ 𝐹 ‘ 𝑥 ) ,  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) ) ) ) | 
						
							| 56 | 18 55 | sylbid | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  𝑘  <  𝐾 )  →  ( 𝑥  =  ( 𝐹 ‘ if ( 𝑘  <  𝐾 ,  𝑘 ,  ( 𝑘  +  1 ) ) )  →  ( 𝑥  ∈  ( 𝑀 ... 𝑁 )  ∧  𝑘  =  if ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾 ,  ( ◡ 𝐹 ‘ 𝑥 ) ,  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) ) ) ) | 
						
							| 57 |  | iffalse | ⊢ ( ¬  𝑘  <  𝐾  →  if ( 𝑘  <  𝐾 ,  𝑘 ,  ( 𝑘  +  1 ) )  =  ( 𝑘  +  1 ) ) | 
						
							| 58 | 57 | fveq2d | ⊢ ( ¬  𝑘  <  𝐾  →  ( 𝐹 ‘ if ( 𝑘  <  𝐾 ,  𝑘 ,  ( 𝑘  +  1 ) ) )  =  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) | 
						
							| 59 | 58 | eqeq2d | ⊢ ( ¬  𝑘  <  𝐾  →  ( 𝑥  =  ( 𝐹 ‘ if ( 𝑘  <  𝐾 ,  𝑘 ,  ( 𝑘  +  1 ) ) )  ↔  𝑥  =  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) ) | 
						
							| 60 | 59 | adantl | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ¬  𝑘  <  𝐾 )  →  ( 𝑥  =  ( 𝐹 ‘ if ( 𝑘  <  𝐾 ,  𝑘 ,  ( 𝑘  +  1 ) ) )  ↔  𝑥  =  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) ) | 
						
							| 61 |  | simprr | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) )  →  𝑥  =  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) | 
						
							| 62 |  | f1ocnv | ⊢ ( 𝐹 : ( 𝑀 ... ( 𝑁  +  1 ) ) –1-1-onto→ ( 𝑀 ... ( 𝑁  +  1 ) )  →  ◡ 𝐹 : ( 𝑀 ... ( 𝑁  +  1 ) ) –1-1-onto→ ( 𝑀 ... ( 𝑁  +  1 ) ) ) | 
						
							| 63 | 6 62 | syl | ⊢ ( 𝜑  →  ◡ 𝐹 : ( 𝑀 ... ( 𝑁  +  1 ) ) –1-1-onto→ ( 𝑀 ... ( 𝑁  +  1 ) ) ) | 
						
							| 64 |  | f1of1 | ⊢ ( ◡ 𝐹 : ( 𝑀 ... ( 𝑁  +  1 ) ) –1-1-onto→ ( 𝑀 ... ( 𝑁  +  1 ) )  →  ◡ 𝐹 : ( 𝑀 ... ( 𝑁  +  1 ) ) –1-1→ ( 𝑀 ... ( 𝑁  +  1 ) ) ) | 
						
							| 65 | 63 64 | syl | ⊢ ( 𝜑  →  ◡ 𝐹 : ( 𝑀 ... ( 𝑁  +  1 ) ) –1-1→ ( 𝑀 ... ( 𝑁  +  1 ) ) ) | 
						
							| 66 |  | f1f | ⊢ ( ◡ 𝐹 : ( 𝑀 ... ( 𝑁  +  1 ) ) –1-1→ ( 𝑀 ... ( 𝑁  +  1 ) )  →  ◡ 𝐹 : ( 𝑀 ... ( 𝑁  +  1 ) ) ⟶ ( 𝑀 ... ( 𝑁  +  1 ) ) ) | 
						
							| 67 | 65 66 | syl | ⊢ ( 𝜑  →  ◡ 𝐹 : ( 𝑀 ... ( 𝑁  +  1 ) ) ⟶ ( 𝑀 ... ( 𝑁  +  1 ) ) ) | 
						
							| 68 |  | peano2uz | ⊢ ( 𝑁  ∈  ( ℤ≥ ‘ 𝑀 )  →  ( 𝑁  +  1 )  ∈  ( ℤ≥ ‘ 𝑀 ) ) | 
						
							| 69 | 4 68 | syl | ⊢ ( 𝜑  →  ( 𝑁  +  1 )  ∈  ( ℤ≥ ‘ 𝑀 ) ) | 
						
							| 70 |  | eluzfz2 | ⊢ ( ( 𝑁  +  1 )  ∈  ( ℤ≥ ‘ 𝑀 )  →  ( 𝑁  +  1 )  ∈  ( 𝑀 ... ( 𝑁  +  1 ) ) ) | 
						
							| 71 | 69 70 | syl | ⊢ ( 𝜑  →  ( 𝑁  +  1 )  ∈  ( 𝑀 ... ( 𝑁  +  1 ) ) ) | 
						
							| 72 | 67 71 | ffvelcdmd | ⊢ ( 𝜑  →  ( ◡ 𝐹 ‘ ( 𝑁  +  1 ) )  ∈  ( 𝑀 ... ( 𝑁  +  1 ) ) ) | 
						
							| 73 | 9 72 | eqeltrid | ⊢ ( 𝜑  →  𝐾  ∈  ( 𝑀 ... ( 𝑁  +  1 ) ) ) | 
						
							| 74 | 73 | elfzelzd | ⊢ ( 𝜑  →  𝐾  ∈  ℤ ) | 
						
							| 75 | 74 | zred | ⊢ ( 𝜑  →  𝐾  ∈  ℝ ) | 
						
							| 76 | 75 | ad2antrr | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) )  →  𝐾  ∈  ℝ ) | 
						
							| 77 | 21 | ad2antlr | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) )  →  𝑘  ∈  ℝ ) | 
						
							| 78 |  | peano2re | ⊢ ( 𝑘  ∈  ℝ  →  ( 𝑘  +  1 )  ∈  ℝ ) | 
						
							| 79 | 77 78 | syl | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) )  →  ( 𝑘  +  1 )  ∈  ℝ ) | 
						
							| 80 |  | simprl | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) )  →  ¬  𝑘  <  𝐾 ) | 
						
							| 81 | 76 77 80 | nltled | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) )  →  𝐾  ≤  𝑘 ) | 
						
							| 82 | 77 | ltp1d | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) )  →  𝑘  <  ( 𝑘  +  1 ) ) | 
						
							| 83 | 76 77 79 81 82 | lelttrd | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) )  →  𝐾  <  ( 𝑘  +  1 ) ) | 
						
							| 84 | 76 83 | ltned | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) )  →  𝐾  ≠  ( 𝑘  +  1 ) ) | 
						
							| 85 | 26 | ad2antrr | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) )  →  𝐹 : ( 𝑀 ... ( 𝑁  +  1 ) ) ⟶ ( 𝑀 ... ( 𝑁  +  1 ) ) ) | 
						
							| 86 |  | fzp1elp1 | ⊢ ( 𝑘  ∈  ( 𝑀 ... 𝑁 )  →  ( 𝑘  +  1 )  ∈  ( 𝑀 ... ( 𝑁  +  1 ) ) ) | 
						
							| 87 | 86 | ad2antlr | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) )  →  ( 𝑘  +  1 )  ∈  ( 𝑀 ... ( 𝑁  +  1 ) ) ) | 
						
							| 88 | 85 87 | ffvelcdmd | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) )  →  ( 𝐹 ‘ ( 𝑘  +  1 ) )  ∈  ( 𝑀 ... ( 𝑁  +  1 ) ) ) | 
						
							| 89 |  | elfzp1 | ⊢ ( 𝑁  ∈  ( ℤ≥ ‘ 𝑀 )  →  ( ( 𝐹 ‘ ( 𝑘  +  1 ) )  ∈  ( 𝑀 ... ( 𝑁  +  1 ) )  ↔  ( ( 𝐹 ‘ ( 𝑘  +  1 ) )  ∈  ( 𝑀 ... 𝑁 )  ∨  ( 𝐹 ‘ ( 𝑘  +  1 ) )  =  ( 𝑁  +  1 ) ) ) ) | 
						
							| 90 | 4 89 | syl | ⊢ ( 𝜑  →  ( ( 𝐹 ‘ ( 𝑘  +  1 ) )  ∈  ( 𝑀 ... ( 𝑁  +  1 ) )  ↔  ( ( 𝐹 ‘ ( 𝑘  +  1 ) )  ∈  ( 𝑀 ... 𝑁 )  ∨  ( 𝐹 ‘ ( 𝑘  +  1 ) )  =  ( 𝑁  +  1 ) ) ) ) | 
						
							| 91 | 90 | ad2antrr | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) )  →  ( ( 𝐹 ‘ ( 𝑘  +  1 ) )  ∈  ( 𝑀 ... ( 𝑁  +  1 ) )  ↔  ( ( 𝐹 ‘ ( 𝑘  +  1 ) )  ∈  ( 𝑀 ... 𝑁 )  ∨  ( 𝐹 ‘ ( 𝑘  +  1 ) )  =  ( 𝑁  +  1 ) ) ) ) | 
						
							| 92 | 88 91 | mpbid | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) )  →  ( ( 𝐹 ‘ ( 𝑘  +  1 ) )  ∈  ( 𝑀 ... 𝑁 )  ∨  ( 𝐹 ‘ ( 𝑘  +  1 ) )  =  ( 𝑁  +  1 ) ) ) | 
						
							| 93 | 92 | ord | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) )  →  ( ¬  ( 𝐹 ‘ ( 𝑘  +  1 ) )  ∈  ( 𝑀 ... 𝑁 )  →  ( 𝐹 ‘ ( 𝑘  +  1 ) )  =  ( 𝑁  +  1 ) ) ) | 
						
							| 94 | 6 | ad2antrr | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) )  →  𝐹 : ( 𝑀 ... ( 𝑁  +  1 ) ) –1-1-onto→ ( 𝑀 ... ( 𝑁  +  1 ) ) ) | 
						
							| 95 |  | f1ocnvfv | ⊢ ( ( 𝐹 : ( 𝑀 ... ( 𝑁  +  1 ) ) –1-1-onto→ ( 𝑀 ... ( 𝑁  +  1 ) )  ∧  ( 𝑘  +  1 )  ∈  ( 𝑀 ... ( 𝑁  +  1 ) ) )  →  ( ( 𝐹 ‘ ( 𝑘  +  1 ) )  =  ( 𝑁  +  1 )  →  ( ◡ 𝐹 ‘ ( 𝑁  +  1 ) )  =  ( 𝑘  +  1 ) ) ) | 
						
							| 96 | 94 87 95 | syl2anc | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) )  →  ( ( 𝐹 ‘ ( 𝑘  +  1 ) )  =  ( 𝑁  +  1 )  →  ( ◡ 𝐹 ‘ ( 𝑁  +  1 ) )  =  ( 𝑘  +  1 ) ) ) | 
						
							| 97 | 9 | eqeq1i | ⊢ ( 𝐾  =  ( 𝑘  +  1 )  ↔  ( ◡ 𝐹 ‘ ( 𝑁  +  1 ) )  =  ( 𝑘  +  1 ) ) | 
						
							| 98 | 96 97 | imbitrrdi | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) )  →  ( ( 𝐹 ‘ ( 𝑘  +  1 ) )  =  ( 𝑁  +  1 )  →  𝐾  =  ( 𝑘  +  1 ) ) ) | 
						
							| 99 | 93 98 | syld | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) )  →  ( ¬  ( 𝐹 ‘ ( 𝑘  +  1 ) )  ∈  ( 𝑀 ... 𝑁 )  →  𝐾  =  ( 𝑘  +  1 ) ) ) | 
						
							| 100 | 99 | necon1ad | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) )  →  ( 𝐾  ≠  ( 𝑘  +  1 )  →  ( 𝐹 ‘ ( 𝑘  +  1 ) )  ∈  ( 𝑀 ... 𝑁 ) ) ) | 
						
							| 101 | 84 100 | mpd | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) )  →  ( 𝐹 ‘ ( 𝑘  +  1 ) )  ∈  ( 𝑀 ... 𝑁 ) ) | 
						
							| 102 | 61 101 | eqeltrd | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) )  →  𝑥  ∈  ( 𝑀 ... 𝑁 ) ) | 
						
							| 103 | 61 | eqcomd | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) )  →  ( 𝐹 ‘ ( 𝑘  +  1 ) )  =  𝑥 ) | 
						
							| 104 |  | f1ocnvfv | ⊢ ( ( 𝐹 : ( 𝑀 ... ( 𝑁  +  1 ) ) –1-1-onto→ ( 𝑀 ... ( 𝑁  +  1 ) )  ∧  ( 𝑘  +  1 )  ∈  ( 𝑀 ... ( 𝑁  +  1 ) ) )  →  ( ( 𝐹 ‘ ( 𝑘  +  1 ) )  =  𝑥  →  ( ◡ 𝐹 ‘ 𝑥 )  =  ( 𝑘  +  1 ) ) ) | 
						
							| 105 | 94 87 104 | syl2anc | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) )  →  ( ( 𝐹 ‘ ( 𝑘  +  1 ) )  =  𝑥  →  ( ◡ 𝐹 ‘ 𝑥 )  =  ( 𝑘  +  1 ) ) ) | 
						
							| 106 | 103 105 | mpd | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) )  →  ( ◡ 𝐹 ‘ 𝑥 )  =  ( 𝑘  +  1 ) ) | 
						
							| 107 | 106 | breq1d | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) )  →  ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ↔  ( 𝑘  +  1 )  <  𝐾 ) ) | 
						
							| 108 |  | lttr | ⊢ ( ( 𝑘  ∈  ℝ  ∧  ( 𝑘  +  1 )  ∈  ℝ  ∧  𝐾  ∈  ℝ )  →  ( ( 𝑘  <  ( 𝑘  +  1 )  ∧  ( 𝑘  +  1 )  <  𝐾 )  →  𝑘  <  𝐾 ) ) | 
						
							| 109 | 77 79 76 108 | syl3anc | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) )  →  ( ( 𝑘  <  ( 𝑘  +  1 )  ∧  ( 𝑘  +  1 )  <  𝐾 )  →  𝑘  <  𝐾 ) ) | 
						
							| 110 | 82 109 | mpand | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) )  →  ( ( 𝑘  +  1 )  <  𝐾  →  𝑘  <  𝐾 ) ) | 
						
							| 111 | 107 110 | sylbid | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) )  →  ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  →  𝑘  <  𝐾 ) ) | 
						
							| 112 | 80 111 | mtod | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) )  →  ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾 ) | 
						
							| 113 |  | iffalse | ⊢ ( ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  →  if ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾 ,  ( ◡ 𝐹 ‘ 𝑥 ) ,  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) )  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) | 
						
							| 114 | 112 113 | syl | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) )  →  if ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾 ,  ( ◡ 𝐹 ‘ 𝑥 ) ,  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) )  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) | 
						
							| 115 | 106 | oveq1d | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) )  →  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 )  =  ( ( 𝑘  +  1 )  −  1 ) ) | 
						
							| 116 | 77 | recnd | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) )  →  𝑘  ∈  ℂ ) | 
						
							| 117 |  | ax-1cn | ⊢ 1  ∈  ℂ | 
						
							| 118 |  | pncan | ⊢ ( ( 𝑘  ∈  ℂ  ∧  1  ∈  ℂ )  →  ( ( 𝑘  +  1 )  −  1 )  =  𝑘 ) | 
						
							| 119 | 116 117 118 | sylancl | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) )  →  ( ( 𝑘  +  1 )  −  1 )  =  𝑘 ) | 
						
							| 120 | 114 115 119 | 3eqtrrd | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) )  →  𝑘  =  if ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾 ,  ( ◡ 𝐹 ‘ 𝑥 ) ,  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) ) | 
						
							| 121 | 102 120 | jca | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  𝑘  <  𝐾  ∧  𝑥  =  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) )  →  ( 𝑥  ∈  ( 𝑀 ... 𝑁 )  ∧  𝑘  =  if ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾 ,  ( ◡ 𝐹 ‘ 𝑥 ) ,  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) ) ) | 
						
							| 122 | 121 | expr | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ¬  𝑘  <  𝐾 )  →  ( 𝑥  =  ( 𝐹 ‘ ( 𝑘  +  1 ) )  →  ( 𝑥  ∈  ( 𝑀 ... 𝑁 )  ∧  𝑘  =  if ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾 ,  ( ◡ 𝐹 ‘ 𝑥 ) ,  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) ) ) ) | 
						
							| 123 | 60 122 | sylbid | ⊢ ( ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ¬  𝑘  <  𝐾 )  →  ( 𝑥  =  ( 𝐹 ‘ if ( 𝑘  <  𝐾 ,  𝑘 ,  ( 𝑘  +  1 ) ) )  →  ( 𝑥  ∈  ( 𝑀 ... 𝑁 )  ∧  𝑘  =  if ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾 ,  ( ◡ 𝐹 ‘ 𝑥 ) ,  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) ) ) ) | 
						
							| 124 | 56 123 | pm2.61dan | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  →  ( 𝑥  =  ( 𝐹 ‘ if ( 𝑘  <  𝐾 ,  𝑘 ,  ( 𝑘  +  1 ) ) )  →  ( 𝑥  ∈  ( 𝑀 ... 𝑁 )  ∧  𝑘  =  if ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾 ,  ( ◡ 𝐹 ‘ 𝑥 ) ,  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) ) ) ) | 
						
							| 125 | 124 | expimpd | ⊢ ( 𝜑  →  ( ( 𝑘  ∈  ( 𝑀 ... 𝑁 )  ∧  𝑥  =  ( 𝐹 ‘ if ( 𝑘  <  𝐾 ,  𝑘 ,  ( 𝑘  +  1 ) ) ) )  →  ( 𝑥  ∈  ( 𝑀 ... 𝑁 )  ∧  𝑘  =  if ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾 ,  ( ◡ 𝐹 ‘ 𝑥 ) ,  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) ) ) ) | 
						
							| 126 | 51 | eqeq2d | ⊢ ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  →  ( 𝑘  =  if ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾 ,  ( ◡ 𝐹 ‘ 𝑥 ) ,  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) )  ↔  𝑘  =  ( ◡ 𝐹 ‘ 𝑥 ) ) ) | 
						
							| 127 | 126 | adantl | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾 )  →  ( 𝑘  =  if ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾 ,  ( ◡ 𝐹 ‘ 𝑥 ) ,  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) )  ↔  𝑘  =  ( ◡ 𝐹 ‘ 𝑥 ) ) ) | 
						
							| 128 |  | eluzel2 | ⊢ ( 𝑁  ∈  ( ℤ≥ ‘ 𝑀 )  →  𝑀  ∈  ℤ ) | 
						
							| 129 | 4 128 | syl | ⊢ ( 𝜑  →  𝑀  ∈  ℤ ) | 
						
							| 130 | 129 | ad2antrr | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ◡ 𝐹 ‘ 𝑥 ) ) )  →  𝑀  ∈  ℤ ) | 
						
							| 131 |  | eluzelz | ⊢ ( 𝑁  ∈  ( ℤ≥ ‘ 𝑀 )  →  𝑁  ∈  ℤ ) | 
						
							| 132 | 4 131 | syl | ⊢ ( 𝜑  →  𝑁  ∈  ℤ ) | 
						
							| 133 | 132 | ad2antrr | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ◡ 𝐹 ‘ 𝑥 ) ) )  →  𝑁  ∈  ℤ ) | 
						
							| 134 |  | simprr | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ◡ 𝐹 ‘ 𝑥 ) ) )  →  𝑘  =  ( ◡ 𝐹 ‘ 𝑥 ) ) | 
						
							| 135 | 67 | ad2antrr | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ◡ 𝐹 ‘ 𝑥 ) ) )  →  ◡ 𝐹 : ( 𝑀 ... ( 𝑁  +  1 ) ) ⟶ ( 𝑀 ... ( 𝑁  +  1 ) ) ) | 
						
							| 136 |  | simplr | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ◡ 𝐹 ‘ 𝑥 ) ) )  →  𝑥  ∈  ( 𝑀 ... 𝑁 ) ) | 
						
							| 137 | 28 136 | sselid | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ◡ 𝐹 ‘ 𝑥 ) ) )  →  𝑥  ∈  ( 𝑀 ... ( 𝑁  +  1 ) ) ) | 
						
							| 138 | 135 137 | ffvelcdmd | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ◡ 𝐹 ‘ 𝑥 ) ) )  →  ( ◡ 𝐹 ‘ 𝑥 )  ∈  ( 𝑀 ... ( 𝑁  +  1 ) ) ) | 
						
							| 139 | 134 138 | eqeltrd | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ◡ 𝐹 ‘ 𝑥 ) ) )  →  𝑘  ∈  ( 𝑀 ... ( 𝑁  +  1 ) ) ) | 
						
							| 140 | 139 | elfzelzd | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ◡ 𝐹 ‘ 𝑥 ) ) )  →  𝑘  ∈  ℤ ) | 
						
							| 141 |  | elfzle1 | ⊢ ( 𝑘  ∈  ( 𝑀 ... ( 𝑁  +  1 ) )  →  𝑀  ≤  𝑘 ) | 
						
							| 142 | 139 141 | syl | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ◡ 𝐹 ‘ 𝑥 ) ) )  →  𝑀  ≤  𝑘 ) | 
						
							| 143 | 140 | zred | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ◡ 𝐹 ‘ 𝑥 ) ) )  →  𝑘  ∈  ℝ ) | 
						
							| 144 | 75 | ad2antrr | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ◡ 𝐹 ‘ 𝑥 ) ) )  →  𝐾  ∈  ℝ ) | 
						
							| 145 | 132 | peano2zd | ⊢ ( 𝜑  →  ( 𝑁  +  1 )  ∈  ℤ ) | 
						
							| 146 | 145 | zred | ⊢ ( 𝜑  →  ( 𝑁  +  1 )  ∈  ℝ ) | 
						
							| 147 | 146 | ad2antrr | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ◡ 𝐹 ‘ 𝑥 ) ) )  →  ( 𝑁  +  1 )  ∈  ℝ ) | 
						
							| 148 |  | simprl | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ◡ 𝐹 ‘ 𝑥 ) ) )  →  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾 ) | 
						
							| 149 | 134 148 | eqbrtrd | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ◡ 𝐹 ‘ 𝑥 ) ) )  →  𝑘  <  𝐾 ) | 
						
							| 150 |  | elfzle2 | ⊢ ( 𝐾  ∈  ( 𝑀 ... ( 𝑁  +  1 ) )  →  𝐾  ≤  ( 𝑁  +  1 ) ) | 
						
							| 151 | 73 150 | syl | ⊢ ( 𝜑  →  𝐾  ≤  ( 𝑁  +  1 ) ) | 
						
							| 152 | 151 | ad2antrr | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ◡ 𝐹 ‘ 𝑥 ) ) )  →  𝐾  ≤  ( 𝑁  +  1 ) ) | 
						
							| 153 | 143 144 147 149 152 | ltletrd | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ◡ 𝐹 ‘ 𝑥 ) ) )  →  𝑘  <  ( 𝑁  +  1 ) ) | 
						
							| 154 |  | zleltp1 | ⊢ ( ( 𝑘  ∈  ℤ  ∧  𝑁  ∈  ℤ )  →  ( 𝑘  ≤  𝑁  ↔  𝑘  <  ( 𝑁  +  1 ) ) ) | 
						
							| 155 | 140 133 154 | syl2anc | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ◡ 𝐹 ‘ 𝑥 ) ) )  →  ( 𝑘  ≤  𝑁  ↔  𝑘  <  ( 𝑁  +  1 ) ) ) | 
						
							| 156 | 153 155 | mpbird | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ◡ 𝐹 ‘ 𝑥 ) ) )  →  𝑘  ≤  𝑁 ) | 
						
							| 157 | 130 133 140 142 156 | elfzd | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ◡ 𝐹 ‘ 𝑥 ) ) )  →  𝑘  ∈  ( 𝑀 ... 𝑁 ) ) | 
						
							| 158 | 149 16 | syl | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ◡ 𝐹 ‘ 𝑥 ) ) )  →  ( 𝐹 ‘ if ( 𝑘  <  𝐾 ,  𝑘 ,  ( 𝑘  +  1 ) ) )  =  ( 𝐹 ‘ 𝑘 ) ) | 
						
							| 159 | 134 | fveq2d | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ◡ 𝐹 ‘ 𝑥 ) ) )  →  ( 𝐹 ‘ 𝑘 )  =  ( 𝐹 ‘ ( ◡ 𝐹 ‘ 𝑥 ) ) ) | 
						
							| 160 | 6 | ad2antrr | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ◡ 𝐹 ‘ 𝑥 ) ) )  →  𝐹 : ( 𝑀 ... ( 𝑁  +  1 ) ) –1-1-onto→ ( 𝑀 ... ( 𝑁  +  1 ) ) ) | 
						
							| 161 |  | f1ocnvfv2 | ⊢ ( ( 𝐹 : ( 𝑀 ... ( 𝑁  +  1 ) ) –1-1-onto→ ( 𝑀 ... ( 𝑁  +  1 ) )  ∧  𝑥  ∈  ( 𝑀 ... ( 𝑁  +  1 ) ) )  →  ( 𝐹 ‘ ( ◡ 𝐹 ‘ 𝑥 ) )  =  𝑥 ) | 
						
							| 162 | 160 137 161 | syl2anc | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ◡ 𝐹 ‘ 𝑥 ) ) )  →  ( 𝐹 ‘ ( ◡ 𝐹 ‘ 𝑥 ) )  =  𝑥 ) | 
						
							| 163 | 158 159 162 | 3eqtrrd | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ◡ 𝐹 ‘ 𝑥 ) ) )  →  𝑥  =  ( 𝐹 ‘ if ( 𝑘  <  𝐾 ,  𝑘 ,  ( 𝑘  +  1 ) ) ) ) | 
						
							| 164 | 157 163 | jca | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ◡ 𝐹 ‘ 𝑥 ) ) )  →  ( 𝑘  ∈  ( 𝑀 ... 𝑁 )  ∧  𝑥  =  ( 𝐹 ‘ if ( 𝑘  <  𝐾 ,  𝑘 ,  ( 𝑘  +  1 ) ) ) ) ) | 
						
							| 165 | 164 | expr | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾 )  →  ( 𝑘  =  ( ◡ 𝐹 ‘ 𝑥 )  →  ( 𝑘  ∈  ( 𝑀 ... 𝑁 )  ∧  𝑥  =  ( 𝐹 ‘ if ( 𝑘  <  𝐾 ,  𝑘 ,  ( 𝑘  +  1 ) ) ) ) ) ) | 
						
							| 166 | 127 165 | sylbid | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾 )  →  ( 𝑘  =  if ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾 ,  ( ◡ 𝐹 ‘ 𝑥 ) ,  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) )  →  ( 𝑘  ∈  ( 𝑀 ... 𝑁 )  ∧  𝑥  =  ( 𝐹 ‘ if ( 𝑘  <  𝐾 ,  𝑘 ,  ( 𝑘  +  1 ) ) ) ) ) ) | 
						
							| 167 | 113 | eqeq2d | ⊢ ( ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  →  ( 𝑘  =  if ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾 ,  ( ◡ 𝐹 ‘ 𝑥 ) ,  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) )  ↔  𝑘  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) ) | 
						
							| 168 | 167 | adantl | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾 )  →  ( 𝑘  =  if ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾 ,  ( ◡ 𝐹 ‘ 𝑥 ) ,  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) )  ↔  𝑘  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) ) | 
						
							| 169 | 129 | ad2antrr | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) )  →  𝑀  ∈  ℤ ) | 
						
							| 170 | 132 | ad2antrr | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) )  →  𝑁  ∈  ℤ ) | 
						
							| 171 |  | simprr | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) )  →  𝑘  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) | 
						
							| 172 | 67 | ad2antrr | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) )  →  ◡ 𝐹 : ( 𝑀 ... ( 𝑁  +  1 ) ) ⟶ ( 𝑀 ... ( 𝑁  +  1 ) ) ) | 
						
							| 173 |  | simplr | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) )  →  𝑥  ∈  ( 𝑀 ... 𝑁 ) ) | 
						
							| 174 | 28 173 | sselid | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) )  →  𝑥  ∈  ( 𝑀 ... ( 𝑁  +  1 ) ) ) | 
						
							| 175 | 172 174 | ffvelcdmd | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) )  →  ( ◡ 𝐹 ‘ 𝑥 )  ∈  ( 𝑀 ... ( 𝑁  +  1 ) ) ) | 
						
							| 176 | 175 | elfzelzd | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) )  →  ( ◡ 𝐹 ‘ 𝑥 )  ∈  ℤ ) | 
						
							| 177 |  | peano2zm | ⊢ ( ( ◡ 𝐹 ‘ 𝑥 )  ∈  ℤ  →  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 )  ∈  ℤ ) | 
						
							| 178 | 176 177 | syl | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) )  →  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 )  ∈  ℤ ) | 
						
							| 179 | 171 178 | eqeltrd | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) )  →  𝑘  ∈  ℤ ) | 
						
							| 180 | 129 | zred | ⊢ ( 𝜑  →  𝑀  ∈  ℝ ) | 
						
							| 181 | 180 | ad2antrr | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) )  →  𝑀  ∈  ℝ ) | 
						
							| 182 | 75 | ad2antrr | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) )  →  𝐾  ∈  ℝ ) | 
						
							| 183 | 179 | zred | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) )  →  𝑘  ∈  ℝ ) | 
						
							| 184 |  | elfzle1 | ⊢ ( 𝐾  ∈  ( 𝑀 ... ( 𝑁  +  1 ) )  →  𝑀  ≤  𝐾 ) | 
						
							| 185 | 73 184 | syl | ⊢ ( 𝜑  →  𝑀  ≤  𝐾 ) | 
						
							| 186 | 185 | ad2antrr | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) )  →  𝑀  ≤  𝐾 ) | 
						
							| 187 | 176 | zred | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) )  →  ( ◡ 𝐹 ‘ 𝑥 )  ∈  ℝ ) | 
						
							| 188 |  | simprl | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) )  →  ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾 ) | 
						
							| 189 | 182 187 188 | nltled | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) )  →  𝐾  ≤  ( ◡ 𝐹 ‘ 𝑥 ) ) | 
						
							| 190 |  | elfzelz | ⊢ ( 𝑥  ∈  ( 𝑀 ... 𝑁 )  →  𝑥  ∈  ℤ ) | 
						
							| 191 | 190 | adantl | ⊢ ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  →  𝑥  ∈  ℤ ) | 
						
							| 192 | 191 | zred | ⊢ ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  →  𝑥  ∈  ℝ ) | 
						
							| 193 | 132 | zred | ⊢ ( 𝜑  →  𝑁  ∈  ℝ ) | 
						
							| 194 | 193 | adantr | ⊢ ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  →  𝑁  ∈  ℝ ) | 
						
							| 195 | 146 | adantr | ⊢ ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  →  ( 𝑁  +  1 )  ∈  ℝ ) | 
						
							| 196 |  | elfzle2 | ⊢ ( 𝑥  ∈  ( 𝑀 ... 𝑁 )  →  𝑥  ≤  𝑁 ) | 
						
							| 197 | 196 | adantl | ⊢ ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  →  𝑥  ≤  𝑁 ) | 
						
							| 198 | 194 | ltp1d | ⊢ ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  →  𝑁  <  ( 𝑁  +  1 ) ) | 
						
							| 199 | 192 194 195 197 198 | lelttrd | ⊢ ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  →  𝑥  <  ( 𝑁  +  1 ) ) | 
						
							| 200 | 192 199 | gtned | ⊢ ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  →  ( 𝑁  +  1 )  ≠  𝑥 ) | 
						
							| 201 | 200 | adantr | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) )  →  ( 𝑁  +  1 )  ≠  𝑥 ) | 
						
							| 202 | 65 | ad2antrr | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) )  →  ◡ 𝐹 : ( 𝑀 ... ( 𝑁  +  1 ) ) –1-1→ ( 𝑀 ... ( 𝑁  +  1 ) ) ) | 
						
							| 203 | 71 | ad2antrr | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) )  →  ( 𝑁  +  1 )  ∈  ( 𝑀 ... ( 𝑁  +  1 ) ) ) | 
						
							| 204 |  | f1fveq | ⊢ ( ( ◡ 𝐹 : ( 𝑀 ... ( 𝑁  +  1 ) ) –1-1→ ( 𝑀 ... ( 𝑁  +  1 ) )  ∧  ( ( 𝑁  +  1 )  ∈  ( 𝑀 ... ( 𝑁  +  1 ) )  ∧  𝑥  ∈  ( 𝑀 ... ( 𝑁  +  1 ) ) ) )  →  ( ( ◡ 𝐹 ‘ ( 𝑁  +  1 ) )  =  ( ◡ 𝐹 ‘ 𝑥 )  ↔  ( 𝑁  +  1 )  =  𝑥 ) ) | 
						
							| 205 | 202 203 174 204 | syl12anc | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) )  →  ( ( ◡ 𝐹 ‘ ( 𝑁  +  1 ) )  =  ( ◡ 𝐹 ‘ 𝑥 )  ↔  ( 𝑁  +  1 )  =  𝑥 ) ) | 
						
							| 206 | 205 | necon3bid | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) )  →  ( ( ◡ 𝐹 ‘ ( 𝑁  +  1 ) )  ≠  ( ◡ 𝐹 ‘ 𝑥 )  ↔  ( 𝑁  +  1 )  ≠  𝑥 ) ) | 
						
							| 207 | 201 206 | mpbird | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) )  →  ( ◡ 𝐹 ‘ ( 𝑁  +  1 ) )  ≠  ( ◡ 𝐹 ‘ 𝑥 ) ) | 
						
							| 208 | 9 | neeq1i | ⊢ ( 𝐾  ≠  ( ◡ 𝐹 ‘ 𝑥 )  ↔  ( ◡ 𝐹 ‘ ( 𝑁  +  1 ) )  ≠  ( ◡ 𝐹 ‘ 𝑥 ) ) | 
						
							| 209 | 207 208 | sylibr | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) )  →  𝐾  ≠  ( ◡ 𝐹 ‘ 𝑥 ) ) | 
						
							| 210 | 209 | necomd | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) )  →  ( ◡ 𝐹 ‘ 𝑥 )  ≠  𝐾 ) | 
						
							| 211 | 182 187 189 210 | leneltd | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) )  →  𝐾  <  ( ◡ 𝐹 ‘ 𝑥 ) ) | 
						
							| 212 | 74 | ad2antrr | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) )  →  𝐾  ∈  ℤ ) | 
						
							| 213 |  | zltlem1 | ⊢ ( ( 𝐾  ∈  ℤ  ∧  ( ◡ 𝐹 ‘ 𝑥 )  ∈  ℤ )  →  ( 𝐾  <  ( ◡ 𝐹 ‘ 𝑥 )  ↔  𝐾  ≤  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) ) | 
						
							| 214 | 212 176 213 | syl2anc | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) )  →  ( 𝐾  <  ( ◡ 𝐹 ‘ 𝑥 )  ↔  𝐾  ≤  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) ) | 
						
							| 215 | 211 214 | mpbid | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) )  →  𝐾  ≤  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) | 
						
							| 216 | 215 171 | breqtrrd | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) )  →  𝐾  ≤  𝑘 ) | 
						
							| 217 | 181 182 183 186 216 | letrd | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) )  →  𝑀  ≤  𝑘 ) | 
						
							| 218 |  | elfzle2 | ⊢ ( ( ◡ 𝐹 ‘ 𝑥 )  ∈  ( 𝑀 ... ( 𝑁  +  1 ) )  →  ( ◡ 𝐹 ‘ 𝑥 )  ≤  ( 𝑁  +  1 ) ) | 
						
							| 219 | 175 218 | syl | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) )  →  ( ◡ 𝐹 ‘ 𝑥 )  ≤  ( 𝑁  +  1 ) ) | 
						
							| 220 | 193 | ad2antrr | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) )  →  𝑁  ∈  ℝ ) | 
						
							| 221 |  | 1re | ⊢ 1  ∈  ℝ | 
						
							| 222 |  | lesubadd | ⊢ ( ( ( ◡ 𝐹 ‘ 𝑥 )  ∈  ℝ  ∧  1  ∈  ℝ  ∧  𝑁  ∈  ℝ )  →  ( ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 )  ≤  𝑁  ↔  ( ◡ 𝐹 ‘ 𝑥 )  ≤  ( 𝑁  +  1 ) ) ) | 
						
							| 223 | 221 222 | mp3an2 | ⊢ ( ( ( ◡ 𝐹 ‘ 𝑥 )  ∈  ℝ  ∧  𝑁  ∈  ℝ )  →  ( ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 )  ≤  𝑁  ↔  ( ◡ 𝐹 ‘ 𝑥 )  ≤  ( 𝑁  +  1 ) ) ) | 
						
							| 224 | 187 220 223 | syl2anc | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) )  →  ( ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 )  ≤  𝑁  ↔  ( ◡ 𝐹 ‘ 𝑥 )  ≤  ( 𝑁  +  1 ) ) ) | 
						
							| 225 | 219 224 | mpbird | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) )  →  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 )  ≤  𝑁 ) | 
						
							| 226 | 171 225 | eqbrtrd | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) )  →  𝑘  ≤  𝑁 ) | 
						
							| 227 | 169 170 179 217 226 | elfzd | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) )  →  𝑘  ∈  ( 𝑀 ... 𝑁 ) ) | 
						
							| 228 | 182 183 216 | lensymd | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) )  →  ¬  𝑘  <  𝐾 ) | 
						
							| 229 | 228 58 | syl | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) )  →  ( 𝐹 ‘ if ( 𝑘  <  𝐾 ,  𝑘 ,  ( 𝑘  +  1 ) ) )  =  ( 𝐹 ‘ ( 𝑘  +  1 ) ) ) | 
						
							| 230 | 171 | oveq1d | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) )  →  ( 𝑘  +  1 )  =  ( ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 )  +  1 ) ) | 
						
							| 231 | 176 | zcnd | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) )  →  ( ◡ 𝐹 ‘ 𝑥 )  ∈  ℂ ) | 
						
							| 232 |  | npcan | ⊢ ( ( ( ◡ 𝐹 ‘ 𝑥 )  ∈  ℂ  ∧  1  ∈  ℂ )  →  ( ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 )  +  1 )  =  ( ◡ 𝐹 ‘ 𝑥 ) ) | 
						
							| 233 | 231 117 232 | sylancl | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) )  →  ( ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 )  +  1 )  =  ( ◡ 𝐹 ‘ 𝑥 ) ) | 
						
							| 234 | 230 233 | eqtrd | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) )  →  ( 𝑘  +  1 )  =  ( ◡ 𝐹 ‘ 𝑥 ) ) | 
						
							| 235 | 234 | fveq2d | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) )  →  ( 𝐹 ‘ ( 𝑘  +  1 ) )  =  ( 𝐹 ‘ ( ◡ 𝐹 ‘ 𝑥 ) ) ) | 
						
							| 236 | 6 | ad2antrr | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) )  →  𝐹 : ( 𝑀 ... ( 𝑁  +  1 ) ) –1-1-onto→ ( 𝑀 ... ( 𝑁  +  1 ) ) ) | 
						
							| 237 | 236 174 161 | syl2anc | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) )  →  ( 𝐹 ‘ ( ◡ 𝐹 ‘ 𝑥 ) )  =  𝑥 ) | 
						
							| 238 | 229 235 237 | 3eqtrrd | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) )  →  𝑥  =  ( 𝐹 ‘ if ( 𝑘  <  𝐾 ,  𝑘 ,  ( 𝑘  +  1 ) ) ) ) | 
						
							| 239 | 227 238 | jca | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ( ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾  ∧  𝑘  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) )  →  ( 𝑘  ∈  ( 𝑀 ... 𝑁 )  ∧  𝑥  =  ( 𝐹 ‘ if ( 𝑘  <  𝐾 ,  𝑘 ,  ( 𝑘  +  1 ) ) ) ) ) | 
						
							| 240 | 239 | expr | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾 )  →  ( 𝑘  =  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 )  →  ( 𝑘  ∈  ( 𝑀 ... 𝑁 )  ∧  𝑥  =  ( 𝐹 ‘ if ( 𝑘  <  𝐾 ,  𝑘 ,  ( 𝑘  +  1 ) ) ) ) ) ) | 
						
							| 241 | 168 240 | sylbid | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  ∧  ¬  ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾 )  →  ( 𝑘  =  if ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾 ,  ( ◡ 𝐹 ‘ 𝑥 ) ,  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) )  →  ( 𝑘  ∈  ( 𝑀 ... 𝑁 )  ∧  𝑥  =  ( 𝐹 ‘ if ( 𝑘  <  𝐾 ,  𝑘 ,  ( 𝑘  +  1 ) ) ) ) ) ) | 
						
							| 242 | 166 241 | pm2.61dan | ⊢ ( ( 𝜑  ∧  𝑥  ∈  ( 𝑀 ... 𝑁 ) )  →  ( 𝑘  =  if ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾 ,  ( ◡ 𝐹 ‘ 𝑥 ) ,  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) )  →  ( 𝑘  ∈  ( 𝑀 ... 𝑁 )  ∧  𝑥  =  ( 𝐹 ‘ if ( 𝑘  <  𝐾 ,  𝑘 ,  ( 𝑘  +  1 ) ) ) ) ) ) | 
						
							| 243 | 242 | expimpd | ⊢ ( 𝜑  →  ( ( 𝑥  ∈  ( 𝑀 ... 𝑁 )  ∧  𝑘  =  if ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾 ,  ( ◡ 𝐹 ‘ 𝑥 ) ,  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) )  →  ( 𝑘  ∈  ( 𝑀 ... 𝑁 )  ∧  𝑥  =  ( 𝐹 ‘ if ( 𝑘  <  𝐾 ,  𝑘 ,  ( 𝑘  +  1 ) ) ) ) ) ) | 
						
							| 244 | 125 243 | impbid | ⊢ ( 𝜑  →  ( ( 𝑘  ∈  ( 𝑀 ... 𝑁 )  ∧  𝑥  =  ( 𝐹 ‘ if ( 𝑘  <  𝐾 ,  𝑘 ,  ( 𝑘  +  1 ) ) ) )  ↔  ( 𝑥  ∈  ( 𝑀 ... 𝑁 )  ∧  𝑘  =  if ( ( ◡ 𝐹 ‘ 𝑥 )  <  𝐾 ,  ( ◡ 𝐹 ‘ 𝑥 ) ,  ( ( ◡ 𝐹 ‘ 𝑥 )  −  1 ) ) ) ) ) | 
						
							| 245 | 8 10 14 244 | f1od | ⊢ ( 𝜑  →  𝐽 : ( 𝑀 ... 𝑁 ) –1-1-onto→ ( 𝑀 ... 𝑁 ) ) |