| Step | Hyp | Ref | Expression | 
						
							| 1 |  | metakunt2.1 | ⊢ ( 𝜑  →  𝑀  ∈  ℕ ) | 
						
							| 2 |  | metakunt2.2 | ⊢ ( 𝜑  →  𝐼  ∈  ℕ ) | 
						
							| 3 |  | metakunt2.3 | ⊢ ( 𝜑  →  𝐼  ≤  𝑀 ) | 
						
							| 4 |  | metakunt2.4 | ⊢ 𝐴  =  ( 𝑥  ∈  ( 1 ... 𝑀 )  ↦  if ( 𝑥  =  𝑀 ,  𝐼 ,  if ( 𝑥  <  𝐼 ,  𝑥 ,  ( 𝑥  +  1 ) ) ) ) | 
						
							| 5 |  | eleq1 | ⊢ ( 𝐼  =  if ( 𝑥  =  𝑀 ,  𝐼 ,  if ( 𝑥  <  𝐼 ,  𝑥 ,  ( 𝑥  +  1 ) ) )  →  ( 𝐼  ∈  ( 1 ... 𝑀 )  ↔  if ( 𝑥  =  𝑀 ,  𝐼 ,  if ( 𝑥  <  𝐼 ,  𝑥 ,  ( 𝑥  +  1 ) ) )  ∈  ( 1 ... 𝑀 ) ) ) | 
						
							| 6 |  | eleq1 | ⊢ ( if ( 𝑥  <  𝐼 ,  𝑥 ,  ( 𝑥  +  1 ) )  =  if ( 𝑥  =  𝑀 ,  𝐼 ,  if ( 𝑥  <  𝐼 ,  𝑥 ,  ( 𝑥  +  1 ) ) )  →  ( if ( 𝑥  <  𝐼 ,  𝑥 ,  ( 𝑥  +  1 ) )  ∈  ( 1 ... 𝑀 )  ↔  if ( 𝑥  =  𝑀 ,  𝐼 ,  if ( 𝑥  <  𝐼 ,  𝑥 ,  ( 𝑥  +  1 ) ) )  ∈  ( 1 ... 𝑀 ) ) ) | 
						
							| 7 |  | 1zzd | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 1 ... 𝑀 ) )  ∧  𝑥  =  𝑀 )  →  1  ∈  ℤ ) | 
						
							| 8 | 1 | nnzd | ⊢ ( 𝜑  →  𝑀  ∈  ℤ ) | 
						
							| 9 | 8 | ad2antrr | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 1 ... 𝑀 ) )  ∧  𝑥  =  𝑀 )  →  𝑀  ∈  ℤ ) | 
						
							| 10 | 2 | nnzd | ⊢ ( 𝜑  →  𝐼  ∈  ℤ ) | 
						
							| 11 | 10 | ad2antrr | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 1 ... 𝑀 ) )  ∧  𝑥  =  𝑀 )  →  𝐼  ∈  ℤ ) | 
						
							| 12 | 2 | nnge1d | ⊢ ( 𝜑  →  1  ≤  𝐼 ) | 
						
							| 13 | 12 | ad2antrr | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 1 ... 𝑀 ) )  ∧  𝑥  =  𝑀 )  →  1  ≤  𝐼 ) | 
						
							| 14 | 3 | ad2antrr | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 1 ... 𝑀 ) )  ∧  𝑥  =  𝑀 )  →  𝐼  ≤  𝑀 ) | 
						
							| 15 | 7 9 11 13 14 | elfzd | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 1 ... 𝑀 ) )  ∧  𝑥  =  𝑀 )  →  𝐼  ∈  ( 1 ... 𝑀 ) ) | 
						
							| 16 |  | eleq1 | ⊢ ( 𝑥  =  if ( 𝑥  <  𝐼 ,  𝑥 ,  ( 𝑥  +  1 ) )  →  ( 𝑥  ∈  ( 1 ... 𝑀 )  ↔  if ( 𝑥  <  𝐼 ,  𝑥 ,  ( 𝑥  +  1 ) )  ∈  ( 1 ... 𝑀 ) ) ) | 
						
							| 17 |  | eleq1 | ⊢ ( ( 𝑥  +  1 )  =  if ( 𝑥  <  𝐼 ,  𝑥 ,  ( 𝑥  +  1 ) )  →  ( ( 𝑥  +  1 )  ∈  ( 1 ... 𝑀 )  ↔  if ( 𝑥  <  𝐼 ,  𝑥 ,  ( 𝑥  +  1 ) )  ∈  ( 1 ... 𝑀 ) ) ) | 
						
							| 18 |  | simpllr | ⊢ ( ( ( ( 𝜑  ∧  𝑥  ∈  ( 1 ... 𝑀 ) )  ∧  ¬  𝑥  =  𝑀 )  ∧  𝑥  <  𝐼 )  →  𝑥  ∈  ( 1 ... 𝑀 ) ) | 
						
							| 19 |  | 1zzd | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 1 ... 𝑀 ) )  ∧  ( ¬  𝑥  =  𝑀  ∧  ¬  𝑥  <  𝐼 ) )  →  1  ∈  ℤ ) | 
						
							| 20 | 8 | ad2antrr | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 1 ... 𝑀 ) )  ∧  ( ¬  𝑥  =  𝑀  ∧  ¬  𝑥  <  𝐼 ) )  →  𝑀  ∈  ℤ ) | 
						
							| 21 |  | elfznn | ⊢ ( 𝑥  ∈  ( 1 ... 𝑀 )  →  𝑥  ∈  ℕ ) | 
						
							| 22 | 21 | nnzd | ⊢ ( 𝑥  ∈  ( 1 ... 𝑀 )  →  𝑥  ∈  ℤ ) | 
						
							| 23 | 22 | ad2antlr | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 1 ... 𝑀 ) )  ∧  ( ¬  𝑥  =  𝑀  ∧  ¬  𝑥  <  𝐼 ) )  →  𝑥  ∈  ℤ ) | 
						
							| 24 | 23 | peano2zd | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 1 ... 𝑀 ) )  ∧  ( ¬  𝑥  =  𝑀  ∧  ¬  𝑥  <  𝐼 ) )  →  ( 𝑥  +  1 )  ∈  ℤ ) | 
						
							| 25 |  | 0p1e1 | ⊢ ( 0  +  1 )  =  1 | 
						
							| 26 |  | 0red | ⊢ ( 𝑥  ∈  ( 1 ... 𝑀 )  →  0  ∈  ℝ ) | 
						
							| 27 | 21 | nnred | ⊢ ( 𝑥  ∈  ( 1 ... 𝑀 )  →  𝑥  ∈  ℝ ) | 
						
							| 28 |  | 1red | ⊢ ( 𝑥  ∈  ( 1 ... 𝑀 )  →  1  ∈  ℝ ) | 
						
							| 29 | 21 | nnnn0d | ⊢ ( 𝑥  ∈  ( 1 ... 𝑀 )  →  𝑥  ∈  ℕ0 ) | 
						
							| 30 | 29 | nn0ge0d | ⊢ ( 𝑥  ∈  ( 1 ... 𝑀 )  →  0  ≤  𝑥 ) | 
						
							| 31 | 26 27 28 30 | leadd1dd | ⊢ ( 𝑥  ∈  ( 1 ... 𝑀 )  →  ( 0  +  1 )  ≤  ( 𝑥  +  1 ) ) | 
						
							| 32 | 25 31 | eqbrtrrid | ⊢ ( 𝑥  ∈  ( 1 ... 𝑀 )  →  1  ≤  ( 𝑥  +  1 ) ) | 
						
							| 33 | 32 | ad2antlr | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 1 ... 𝑀 ) )  ∧  ( ¬  𝑥  =  𝑀  ∧  ¬  𝑥  <  𝐼 ) )  →  1  ≤  ( 𝑥  +  1 ) ) | 
						
							| 34 |  | simplr | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 1 ... 𝑀 ) )  ∧  ¬  𝑥  =  𝑀 )  →  𝑥  ∈  ( 1 ... 𝑀 ) ) | 
						
							| 35 |  | neqne | ⊢ ( ¬  𝑥  =  𝑀  →  𝑥  ≠  𝑀 ) | 
						
							| 36 | 35 | adantl | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 1 ... 𝑀 ) )  ∧  ¬  𝑥  =  𝑀 )  →  𝑥  ≠  𝑀 ) | 
						
							| 37 | 34 36 | fzne2d | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 1 ... 𝑀 ) )  ∧  ¬  𝑥  =  𝑀 )  →  𝑥  <  𝑀 ) | 
						
							| 38 | 37 | adantrr | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 1 ... 𝑀 ) )  ∧  ( ¬  𝑥  =  𝑀  ∧  ¬  𝑥  <  𝐼 ) )  →  𝑥  <  𝑀 ) | 
						
							| 39 | 22 | adantl | ⊢ ( ( 𝜑  ∧  𝑥  ∈  ( 1 ... 𝑀 ) )  →  𝑥  ∈  ℤ ) | 
						
							| 40 | 8 | adantr | ⊢ ( ( 𝜑  ∧  𝑥  ∈  ( 1 ... 𝑀 ) )  →  𝑀  ∈  ℤ ) | 
						
							| 41 | 39 40 | zltp1led | ⊢ ( ( 𝜑  ∧  𝑥  ∈  ( 1 ... 𝑀 ) )  →  ( 𝑥  <  𝑀  ↔  ( 𝑥  +  1 )  ≤  𝑀 ) ) | 
						
							| 42 | 41 | adantr | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 1 ... 𝑀 ) )  ∧  ( ¬  𝑥  =  𝑀  ∧  ¬  𝑥  <  𝐼 ) )  →  ( 𝑥  <  𝑀  ↔  ( 𝑥  +  1 )  ≤  𝑀 ) ) | 
						
							| 43 | 38 42 | mpbid | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 1 ... 𝑀 ) )  ∧  ( ¬  𝑥  =  𝑀  ∧  ¬  𝑥  <  𝐼 ) )  →  ( 𝑥  +  1 )  ≤  𝑀 ) | 
						
							| 44 | 19 20 24 33 43 | elfzd | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 1 ... 𝑀 ) )  ∧  ( ¬  𝑥  =  𝑀  ∧  ¬  𝑥  <  𝐼 ) )  →  ( 𝑥  +  1 )  ∈  ( 1 ... 𝑀 ) ) | 
						
							| 45 | 44 | anassrs | ⊢ ( ( ( ( 𝜑  ∧  𝑥  ∈  ( 1 ... 𝑀 ) )  ∧  ¬  𝑥  =  𝑀 )  ∧  ¬  𝑥  <  𝐼 )  →  ( 𝑥  +  1 )  ∈  ( 1 ... 𝑀 ) ) | 
						
							| 46 | 16 17 18 45 | ifbothda | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ( 1 ... 𝑀 ) )  ∧  ¬  𝑥  =  𝑀 )  →  if ( 𝑥  <  𝐼 ,  𝑥 ,  ( 𝑥  +  1 ) )  ∈  ( 1 ... 𝑀 ) ) | 
						
							| 47 | 5 6 15 46 | ifbothda | ⊢ ( ( 𝜑  ∧  𝑥  ∈  ( 1 ... 𝑀 ) )  →  if ( 𝑥  =  𝑀 ,  𝐼 ,  if ( 𝑥  <  𝐼 ,  𝑥 ,  ( 𝑥  +  1 ) ) )  ∈  ( 1 ... 𝑀 ) ) | 
						
							| 48 | 47 4 | fmptd | ⊢ ( 𝜑  →  𝐴 : ( 1 ... 𝑀 ) ⟶ ( 1 ... 𝑀 ) ) |