| Step | Hyp | Ref | Expression | 
						
							| 1 |  | metakunt28.1 | ⊢ ( 𝜑  →  𝑀  ∈  ℕ ) | 
						
							| 2 |  | metakunt28.2 | ⊢ ( 𝜑  →  𝐼  ∈  ℕ ) | 
						
							| 3 |  | metakunt28.3 | ⊢ ( 𝜑  →  𝐼  ≤  𝑀 ) | 
						
							| 4 |  | metakunt28.4 | ⊢ ( 𝜑  →  𝑋  ∈  ( 1 ... 𝑀 ) ) | 
						
							| 5 |  | metakunt28.5 | ⊢ 𝐴  =  ( 𝑥  ∈  ( 1 ... 𝑀 )  ↦  if ( 𝑥  =  𝐼 ,  𝑀 ,  if ( 𝑥  <  𝐼 ,  𝑥 ,  ( 𝑥  −  1 ) ) ) ) | 
						
							| 6 |  | metakunt28.6 | ⊢ 𝐵  =  ( 𝑧  ∈  ( 1 ... 𝑀 )  ↦  if ( 𝑧  =  𝑀 ,  𝑀 ,  if ( 𝑧  <  𝐼 ,  ( 𝑧  +  ( 𝑀  −  𝐼 ) ) ,  ( 𝑧  +  ( 1  −  𝐼 ) ) ) ) ) | 
						
							| 7 |  | metakunt28.7 | ⊢ ( 𝜑  →  ¬  𝑋  =  𝐼 ) | 
						
							| 8 |  | metakunt28.8 | ⊢ ( 𝜑  →  ¬  𝑋  <  𝐼 ) | 
						
							| 9 | 5 | a1i | ⊢ ( 𝜑  →  𝐴  =  ( 𝑥  ∈  ( 1 ... 𝑀 )  ↦  if ( 𝑥  =  𝐼 ,  𝑀 ,  if ( 𝑥  <  𝐼 ,  𝑥 ,  ( 𝑥  −  1 ) ) ) ) ) | 
						
							| 10 | 7 | adantr | ⊢ ( ( 𝜑  ∧  𝑥  =  𝑋 )  →  ¬  𝑋  =  𝐼 ) | 
						
							| 11 |  | simpr | ⊢ ( ( 𝜑  ∧  𝑥  =  𝑋 )  →  𝑥  =  𝑋 ) | 
						
							| 12 | 11 | eqeq1d | ⊢ ( ( 𝜑  ∧  𝑥  =  𝑋 )  →  ( 𝑥  =  𝐼  ↔  𝑋  =  𝐼 ) ) | 
						
							| 13 | 12 | notbid | ⊢ ( ( 𝜑  ∧  𝑥  =  𝑋 )  →  ( ¬  𝑥  =  𝐼  ↔  ¬  𝑋  =  𝐼 ) ) | 
						
							| 14 | 10 13 | mpbird | ⊢ ( ( 𝜑  ∧  𝑥  =  𝑋 )  →  ¬  𝑥  =  𝐼 ) | 
						
							| 15 | 14 | iffalsed | ⊢ ( ( 𝜑  ∧  𝑥  =  𝑋 )  →  if ( 𝑥  =  𝐼 ,  𝑀 ,  if ( 𝑥  <  𝐼 ,  𝑥 ,  ( 𝑥  −  1 ) ) )  =  if ( 𝑥  <  𝐼 ,  𝑥 ,  ( 𝑥  −  1 ) ) ) | 
						
							| 16 | 8 | adantr | ⊢ ( ( 𝜑  ∧  𝑥  =  𝑋 )  →  ¬  𝑋  <  𝐼 ) | 
						
							| 17 | 11 | breq1d | ⊢ ( ( 𝜑  ∧  𝑥  =  𝑋 )  →  ( 𝑥  <  𝐼  ↔  𝑋  <  𝐼 ) ) | 
						
							| 18 | 17 | notbid | ⊢ ( ( 𝜑  ∧  𝑥  =  𝑋 )  →  ( ¬  𝑥  <  𝐼  ↔  ¬  𝑋  <  𝐼 ) ) | 
						
							| 19 | 16 18 | mpbird | ⊢ ( ( 𝜑  ∧  𝑥  =  𝑋 )  →  ¬  𝑥  <  𝐼 ) | 
						
							| 20 | 19 | iffalsed | ⊢ ( ( 𝜑  ∧  𝑥  =  𝑋 )  →  if ( 𝑥  <  𝐼 ,  𝑥 ,  ( 𝑥  −  1 ) )  =  ( 𝑥  −  1 ) ) | 
						
							| 21 | 11 | oveq1d | ⊢ ( ( 𝜑  ∧  𝑥  =  𝑋 )  →  ( 𝑥  −  1 )  =  ( 𝑋  −  1 ) ) | 
						
							| 22 | 20 21 | eqtrd | ⊢ ( ( 𝜑  ∧  𝑥  =  𝑋 )  →  if ( 𝑥  <  𝐼 ,  𝑥 ,  ( 𝑥  −  1 ) )  =  ( 𝑋  −  1 ) ) | 
						
							| 23 | 15 22 | eqtrd | ⊢ ( ( 𝜑  ∧  𝑥  =  𝑋 )  →  if ( 𝑥  =  𝐼 ,  𝑀 ,  if ( 𝑥  <  𝐼 ,  𝑥 ,  ( 𝑥  −  1 ) ) )  =  ( 𝑋  −  1 ) ) | 
						
							| 24 | 4 | elfzelzd | ⊢ ( 𝜑  →  𝑋  ∈  ℤ ) | 
						
							| 25 |  | 1zzd | ⊢ ( 𝜑  →  1  ∈  ℤ ) | 
						
							| 26 | 24 25 | zsubcld | ⊢ ( 𝜑  →  ( 𝑋  −  1 )  ∈  ℤ ) | 
						
							| 27 | 9 23 4 26 | fvmptd | ⊢ ( 𝜑  →  ( 𝐴 ‘ 𝑋 )  =  ( 𝑋  −  1 ) ) | 
						
							| 28 | 27 | fveq2d | ⊢ ( 𝜑  →  ( 𝐵 ‘ ( 𝐴 ‘ 𝑋 ) )  =  ( 𝐵 ‘ ( 𝑋  −  1 ) ) ) | 
						
							| 29 | 6 | a1i | ⊢ ( 𝜑  →  𝐵  =  ( 𝑧  ∈  ( 1 ... 𝑀 )  ↦  if ( 𝑧  =  𝑀 ,  𝑀 ,  if ( 𝑧  <  𝐼 ,  ( 𝑧  +  ( 𝑀  −  𝐼 ) ) ,  ( 𝑧  +  ( 1  −  𝐼 ) ) ) ) ) ) | 
						
							| 30 | 26 | zred | ⊢ ( 𝜑  →  ( 𝑋  −  1 )  ∈  ℝ ) | 
						
							| 31 | 24 | zred | ⊢ ( 𝜑  →  𝑋  ∈  ℝ ) | 
						
							| 32 | 1 | nnred | ⊢ ( 𝜑  →  𝑀  ∈  ℝ ) | 
						
							| 33 |  | 1rp | ⊢ 1  ∈  ℝ+ | 
						
							| 34 | 33 | a1i | ⊢ ( 𝜑  →  1  ∈  ℝ+ ) | 
						
							| 35 | 31 34 | ltsubrpd | ⊢ ( 𝜑  →  ( 𝑋  −  1 )  <  𝑋 ) | 
						
							| 36 |  | elfzle2 | ⊢ ( 𝑋  ∈  ( 1 ... 𝑀 )  →  𝑋  ≤  𝑀 ) | 
						
							| 37 | 4 36 | syl | ⊢ ( 𝜑  →  𝑋  ≤  𝑀 ) | 
						
							| 38 | 30 31 32 35 37 | ltletrd | ⊢ ( 𝜑  →  ( 𝑋  −  1 )  <  𝑀 ) | 
						
							| 39 | 30 38 | ltned | ⊢ ( 𝜑  →  ( 𝑋  −  1 )  ≠  𝑀 ) | 
						
							| 40 | 39 | adantr | ⊢ ( ( 𝜑  ∧  𝑧  =  ( 𝑋  −  1 ) )  →  ( 𝑋  −  1 )  ≠  𝑀 ) | 
						
							| 41 | 40 | neneqd | ⊢ ( ( 𝜑  ∧  𝑧  =  ( 𝑋  −  1 ) )  →  ¬  ( 𝑋  −  1 )  =  𝑀 ) | 
						
							| 42 |  | simpr | ⊢ ( ( 𝜑  ∧  𝑧  =  ( 𝑋  −  1 ) )  →  𝑧  =  ( 𝑋  −  1 ) ) | 
						
							| 43 | 42 | eqeq1d | ⊢ ( ( 𝜑  ∧  𝑧  =  ( 𝑋  −  1 ) )  →  ( 𝑧  =  𝑀  ↔  ( 𝑋  −  1 )  =  𝑀 ) ) | 
						
							| 44 | 43 | notbid | ⊢ ( ( 𝜑  ∧  𝑧  =  ( 𝑋  −  1 ) )  →  ( ¬  𝑧  =  𝑀  ↔  ¬  ( 𝑋  −  1 )  =  𝑀 ) ) | 
						
							| 45 | 41 44 | mpbird | ⊢ ( ( 𝜑  ∧  𝑧  =  ( 𝑋  −  1 ) )  →  ¬  𝑧  =  𝑀 ) | 
						
							| 46 | 45 | iffalsed | ⊢ ( ( 𝜑  ∧  𝑧  =  ( 𝑋  −  1 ) )  →  if ( 𝑧  =  𝑀 ,  𝑀 ,  if ( 𝑧  <  𝐼 ,  ( 𝑧  +  ( 𝑀  −  𝐼 ) ) ,  ( 𝑧  +  ( 1  −  𝐼 ) ) ) )  =  if ( 𝑧  <  𝐼 ,  ( 𝑧  +  ( 𝑀  −  𝐼 ) ) ,  ( 𝑧  +  ( 1  −  𝐼 ) ) ) ) | 
						
							| 47 | 7 | neqned | ⊢ ( 𝜑  →  𝑋  ≠  𝐼 ) | 
						
							| 48 | 2 | nnred | ⊢ ( 𝜑  →  𝐼  ∈  ℝ ) | 
						
							| 49 | 48 31 8 | nltled | ⊢ ( 𝜑  →  𝐼  ≤  𝑋 ) | 
						
							| 50 | 48 31 49 | leltned | ⊢ ( 𝜑  →  ( 𝐼  <  𝑋  ↔  𝑋  ≠  𝐼 ) ) | 
						
							| 51 | 47 50 | mpbird | ⊢ ( 𝜑  →  𝐼  <  𝑋 ) | 
						
							| 52 | 2 | nnzd | ⊢ ( 𝜑  →  𝐼  ∈  ℤ ) | 
						
							| 53 | 52 24 | zltlem1d | ⊢ ( 𝜑  →  ( 𝐼  <  𝑋  ↔  𝐼  ≤  ( 𝑋  −  1 ) ) ) | 
						
							| 54 | 51 53 | mpbid | ⊢ ( 𝜑  →  𝐼  ≤  ( 𝑋  −  1 ) ) | 
						
							| 55 | 48 30 | lenltd | ⊢ ( 𝜑  →  ( 𝐼  ≤  ( 𝑋  −  1 )  ↔  ¬  ( 𝑋  −  1 )  <  𝐼 ) ) | 
						
							| 56 | 54 55 | mpbid | ⊢ ( 𝜑  →  ¬  ( 𝑋  −  1 )  <  𝐼 ) | 
						
							| 57 | 56 | adantr | ⊢ ( ( 𝜑  ∧  𝑧  =  ( 𝑋  −  1 ) )  →  ¬  ( 𝑋  −  1 )  <  𝐼 ) | 
						
							| 58 | 42 | breq1d | ⊢ ( ( 𝜑  ∧  𝑧  =  ( 𝑋  −  1 ) )  →  ( 𝑧  <  𝐼  ↔  ( 𝑋  −  1 )  <  𝐼 ) ) | 
						
							| 59 | 58 | notbid | ⊢ ( ( 𝜑  ∧  𝑧  =  ( 𝑋  −  1 ) )  →  ( ¬  𝑧  <  𝐼  ↔  ¬  ( 𝑋  −  1 )  <  𝐼 ) ) | 
						
							| 60 | 57 59 | mpbird | ⊢ ( ( 𝜑  ∧  𝑧  =  ( 𝑋  −  1 ) )  →  ¬  𝑧  <  𝐼 ) | 
						
							| 61 | 60 | iffalsed | ⊢ ( ( 𝜑  ∧  𝑧  =  ( 𝑋  −  1 ) )  →  if ( 𝑧  <  𝐼 ,  ( 𝑧  +  ( 𝑀  −  𝐼 ) ) ,  ( 𝑧  +  ( 1  −  𝐼 ) ) )  =  ( 𝑧  +  ( 1  −  𝐼 ) ) ) | 
						
							| 62 | 42 | oveq1d | ⊢ ( ( 𝜑  ∧  𝑧  =  ( 𝑋  −  1 ) )  →  ( 𝑧  +  ( 1  −  𝐼 ) )  =  ( ( 𝑋  −  1 )  +  ( 1  −  𝐼 ) ) ) | 
						
							| 63 | 24 | zcnd | ⊢ ( 𝜑  →  𝑋  ∈  ℂ ) | 
						
							| 64 |  | 1cnd | ⊢ ( 𝜑  →  1  ∈  ℂ ) | 
						
							| 65 | 2 | nncnd | ⊢ ( 𝜑  →  𝐼  ∈  ℂ ) | 
						
							| 66 | 63 64 65 | npncand | ⊢ ( 𝜑  →  ( ( 𝑋  −  1 )  +  ( 1  −  𝐼 ) )  =  ( 𝑋  −  𝐼 ) ) | 
						
							| 67 | 66 | adantr | ⊢ ( ( 𝜑  ∧  𝑧  =  ( 𝑋  −  1 ) )  →  ( ( 𝑋  −  1 )  +  ( 1  −  𝐼 ) )  =  ( 𝑋  −  𝐼 ) ) | 
						
							| 68 | 62 67 | eqtrd | ⊢ ( ( 𝜑  ∧  𝑧  =  ( 𝑋  −  1 ) )  →  ( 𝑧  +  ( 1  −  𝐼 ) )  =  ( 𝑋  −  𝐼 ) ) | 
						
							| 69 | 61 68 | eqtrd | ⊢ ( ( 𝜑  ∧  𝑧  =  ( 𝑋  −  1 ) )  →  if ( 𝑧  <  𝐼 ,  ( 𝑧  +  ( 𝑀  −  𝐼 ) ) ,  ( 𝑧  +  ( 1  −  𝐼 ) ) )  =  ( 𝑋  −  𝐼 ) ) | 
						
							| 70 | 46 69 | eqtrd | ⊢ ( ( 𝜑  ∧  𝑧  =  ( 𝑋  −  1 ) )  →  if ( 𝑧  =  𝑀 ,  𝑀 ,  if ( 𝑧  <  𝐼 ,  ( 𝑧  +  ( 𝑀  −  𝐼 ) ) ,  ( 𝑧  +  ( 1  −  𝐼 ) ) ) )  =  ( 𝑋  −  𝐼 ) ) | 
						
							| 71 | 1 | nnzd | ⊢ ( 𝜑  →  𝑀  ∈  ℤ ) | 
						
							| 72 |  | 1red | ⊢ ( 𝜑  →  1  ∈  ℝ ) | 
						
							| 73 | 2 | nnge1d | ⊢ ( 𝜑  →  1  ≤  𝐼 ) | 
						
							| 74 | 72 48 31 73 51 | lelttrd | ⊢ ( 𝜑  →  1  <  𝑋 ) | 
						
							| 75 | 25 24 | zltlem1d | ⊢ ( 𝜑  →  ( 1  <  𝑋  ↔  1  ≤  ( 𝑋  −  1 ) ) ) | 
						
							| 76 | 74 75 | mpbid | ⊢ ( 𝜑  →  1  ≤  ( 𝑋  −  1 ) ) | 
						
							| 77 | 31 72 | resubcld | ⊢ ( 𝜑  →  ( 𝑋  −  1 )  ∈  ℝ ) | 
						
							| 78 |  | 0le1 | ⊢ 0  ≤  1 | 
						
							| 79 | 78 | a1i | ⊢ ( 𝜑  →  0  ≤  1 ) | 
						
							| 80 | 31 72 | subge02d | ⊢ ( 𝜑  →  ( 0  ≤  1  ↔  ( 𝑋  −  1 )  ≤  𝑋 ) ) | 
						
							| 81 | 79 80 | mpbid | ⊢ ( 𝜑  →  ( 𝑋  −  1 )  ≤  𝑋 ) | 
						
							| 82 | 77 31 32 81 37 | letrd | ⊢ ( 𝜑  →  ( 𝑋  −  1 )  ≤  𝑀 ) | 
						
							| 83 | 25 71 26 76 82 | elfzd | ⊢ ( 𝜑  →  ( 𝑋  −  1 )  ∈  ( 1 ... 𝑀 ) ) | 
						
							| 84 | 24 52 | zsubcld | ⊢ ( 𝜑  →  ( 𝑋  −  𝐼 )  ∈  ℤ ) | 
						
							| 85 | 29 70 83 84 | fvmptd | ⊢ ( 𝜑  →  ( 𝐵 ‘ ( 𝑋  −  1 ) )  =  ( 𝑋  −  𝐼 ) ) | 
						
							| 86 | 28 85 | eqtrd | ⊢ ( 𝜑  →  ( 𝐵 ‘ ( 𝐴 ‘ 𝑋 ) )  =  ( 𝑋  −  𝐼 ) ) |