| Step | Hyp | Ref | Expression | 
						
							| 1 |  | id | ⊢ ( 𝑎  =  0  →  𝑎  =  0 ) | 
						
							| 2 |  | oveq2 | ⊢ ( 𝑎  =  0  →  ( 𝐴  Yrm  𝑎 )  =  ( 𝐴  Yrm  0 ) ) | 
						
							| 3 | 1 2 | breq12d | ⊢ ( 𝑎  =  0  →  ( 𝑎  ≤  ( 𝐴  Yrm  𝑎 )  ↔  0  ≤  ( 𝐴  Yrm  0 ) ) ) | 
						
							| 4 | 3 | imbi2d | ⊢ ( 𝑎  =  0  →  ( ( 𝐴  ∈  ( ℤ≥ ‘ 2 )  →  𝑎  ≤  ( 𝐴  Yrm  𝑎 ) )  ↔  ( 𝐴  ∈  ( ℤ≥ ‘ 2 )  →  0  ≤  ( 𝐴  Yrm  0 ) ) ) ) | 
						
							| 5 |  | id | ⊢ ( 𝑎  =  𝑏  →  𝑎  =  𝑏 ) | 
						
							| 6 |  | oveq2 | ⊢ ( 𝑎  =  𝑏  →  ( 𝐴  Yrm  𝑎 )  =  ( 𝐴  Yrm  𝑏 ) ) | 
						
							| 7 | 5 6 | breq12d | ⊢ ( 𝑎  =  𝑏  →  ( 𝑎  ≤  ( 𝐴  Yrm  𝑎 )  ↔  𝑏  ≤  ( 𝐴  Yrm  𝑏 ) ) ) | 
						
							| 8 | 7 | imbi2d | ⊢ ( 𝑎  =  𝑏  →  ( ( 𝐴  ∈  ( ℤ≥ ‘ 2 )  →  𝑎  ≤  ( 𝐴  Yrm  𝑎 ) )  ↔  ( 𝐴  ∈  ( ℤ≥ ‘ 2 )  →  𝑏  ≤  ( 𝐴  Yrm  𝑏 ) ) ) ) | 
						
							| 9 |  | id | ⊢ ( 𝑎  =  ( 𝑏  +  1 )  →  𝑎  =  ( 𝑏  +  1 ) ) | 
						
							| 10 |  | oveq2 | ⊢ ( 𝑎  =  ( 𝑏  +  1 )  →  ( 𝐴  Yrm  𝑎 )  =  ( 𝐴  Yrm  ( 𝑏  +  1 ) ) ) | 
						
							| 11 | 9 10 | breq12d | ⊢ ( 𝑎  =  ( 𝑏  +  1 )  →  ( 𝑎  ≤  ( 𝐴  Yrm  𝑎 )  ↔  ( 𝑏  +  1 )  ≤  ( 𝐴  Yrm  ( 𝑏  +  1 ) ) ) ) | 
						
							| 12 | 11 | imbi2d | ⊢ ( 𝑎  =  ( 𝑏  +  1 )  →  ( ( 𝐴  ∈  ( ℤ≥ ‘ 2 )  →  𝑎  ≤  ( 𝐴  Yrm  𝑎 ) )  ↔  ( 𝐴  ∈  ( ℤ≥ ‘ 2 )  →  ( 𝑏  +  1 )  ≤  ( 𝐴  Yrm  ( 𝑏  +  1 ) ) ) ) ) | 
						
							| 13 |  | id | ⊢ ( 𝑎  =  𝑁  →  𝑎  =  𝑁 ) | 
						
							| 14 |  | oveq2 | ⊢ ( 𝑎  =  𝑁  →  ( 𝐴  Yrm  𝑎 )  =  ( 𝐴  Yrm  𝑁 ) ) | 
						
							| 15 | 13 14 | breq12d | ⊢ ( 𝑎  =  𝑁  →  ( 𝑎  ≤  ( 𝐴  Yrm  𝑎 )  ↔  𝑁  ≤  ( 𝐴  Yrm  𝑁 ) ) ) | 
						
							| 16 | 15 | imbi2d | ⊢ ( 𝑎  =  𝑁  →  ( ( 𝐴  ∈  ( ℤ≥ ‘ 2 )  →  𝑎  ≤  ( 𝐴  Yrm  𝑎 ) )  ↔  ( 𝐴  ∈  ( ℤ≥ ‘ 2 )  →  𝑁  ≤  ( 𝐴  Yrm  𝑁 ) ) ) ) | 
						
							| 17 |  | 0le0 | ⊢ 0  ≤  0 | 
						
							| 18 |  | rmy0 | ⊢ ( 𝐴  ∈  ( ℤ≥ ‘ 2 )  →  ( 𝐴  Yrm  0 )  =  0 ) | 
						
							| 19 | 17 18 | breqtrrid | ⊢ ( 𝐴  ∈  ( ℤ≥ ‘ 2 )  →  0  ≤  ( 𝐴  Yrm  0 ) ) | 
						
							| 20 |  | nn0z | ⊢ ( 𝑏  ∈  ℕ0  →  𝑏  ∈  ℤ ) | 
						
							| 21 | 20 | 3ad2ant1 | ⊢ ( ( 𝑏  ∈  ℕ0  ∧  𝐴  ∈  ( ℤ≥ ‘ 2 )  ∧  𝑏  ≤  ( 𝐴  Yrm  𝑏 ) )  →  𝑏  ∈  ℤ ) | 
						
							| 22 | 21 | peano2zd | ⊢ ( ( 𝑏  ∈  ℕ0  ∧  𝐴  ∈  ( ℤ≥ ‘ 2 )  ∧  𝑏  ≤  ( 𝐴  Yrm  𝑏 ) )  →  ( 𝑏  +  1 )  ∈  ℤ ) | 
						
							| 23 | 22 | zred | ⊢ ( ( 𝑏  ∈  ℕ0  ∧  𝐴  ∈  ( ℤ≥ ‘ 2 )  ∧  𝑏  ≤  ( 𝐴  Yrm  𝑏 ) )  →  ( 𝑏  +  1 )  ∈  ℝ ) | 
						
							| 24 |  | simp2 | ⊢ ( ( 𝑏  ∈  ℕ0  ∧  𝐴  ∈  ( ℤ≥ ‘ 2 )  ∧  𝑏  ≤  ( 𝐴  Yrm  𝑏 ) )  →  𝐴  ∈  ( ℤ≥ ‘ 2 ) ) | 
						
							| 25 |  | frmy | ⊢  Yrm  : ( ( ℤ≥ ‘ 2 )  ×  ℤ ) ⟶ ℤ | 
						
							| 26 | 25 | fovcl | ⊢ ( ( 𝐴  ∈  ( ℤ≥ ‘ 2 )  ∧  𝑏  ∈  ℤ )  →  ( 𝐴  Yrm  𝑏 )  ∈  ℤ ) | 
						
							| 27 | 24 21 26 | syl2anc | ⊢ ( ( 𝑏  ∈  ℕ0  ∧  𝐴  ∈  ( ℤ≥ ‘ 2 )  ∧  𝑏  ≤  ( 𝐴  Yrm  𝑏 ) )  →  ( 𝐴  Yrm  𝑏 )  ∈  ℤ ) | 
						
							| 28 | 27 | peano2zd | ⊢ ( ( 𝑏  ∈  ℕ0  ∧  𝐴  ∈  ( ℤ≥ ‘ 2 )  ∧  𝑏  ≤  ( 𝐴  Yrm  𝑏 ) )  →  ( ( 𝐴  Yrm  𝑏 )  +  1 )  ∈  ℤ ) | 
						
							| 29 | 28 | zred | ⊢ ( ( 𝑏  ∈  ℕ0  ∧  𝐴  ∈  ( ℤ≥ ‘ 2 )  ∧  𝑏  ≤  ( 𝐴  Yrm  𝑏 ) )  →  ( ( 𝐴  Yrm  𝑏 )  +  1 )  ∈  ℝ ) | 
						
							| 30 | 25 | fovcl | ⊢ ( ( 𝐴  ∈  ( ℤ≥ ‘ 2 )  ∧  ( 𝑏  +  1 )  ∈  ℤ )  →  ( 𝐴  Yrm  ( 𝑏  +  1 ) )  ∈  ℤ ) | 
						
							| 31 | 24 22 30 | syl2anc | ⊢ ( ( 𝑏  ∈  ℕ0  ∧  𝐴  ∈  ( ℤ≥ ‘ 2 )  ∧  𝑏  ≤  ( 𝐴  Yrm  𝑏 ) )  →  ( 𝐴  Yrm  ( 𝑏  +  1 ) )  ∈  ℤ ) | 
						
							| 32 | 31 | zred | ⊢ ( ( 𝑏  ∈  ℕ0  ∧  𝐴  ∈  ( ℤ≥ ‘ 2 )  ∧  𝑏  ≤  ( 𝐴  Yrm  𝑏 ) )  →  ( 𝐴  Yrm  ( 𝑏  +  1 ) )  ∈  ℝ ) | 
						
							| 33 |  | nn0re | ⊢ ( 𝑏  ∈  ℕ0  →  𝑏  ∈  ℝ ) | 
						
							| 34 | 33 | 3ad2ant1 | ⊢ ( ( 𝑏  ∈  ℕ0  ∧  𝐴  ∈  ( ℤ≥ ‘ 2 )  ∧  𝑏  ≤  ( 𝐴  Yrm  𝑏 ) )  →  𝑏  ∈  ℝ ) | 
						
							| 35 | 27 | zred | ⊢ ( ( 𝑏  ∈  ℕ0  ∧  𝐴  ∈  ( ℤ≥ ‘ 2 )  ∧  𝑏  ≤  ( 𝐴  Yrm  𝑏 ) )  →  ( 𝐴  Yrm  𝑏 )  ∈  ℝ ) | 
						
							| 36 |  | 1red | ⊢ ( ( 𝑏  ∈  ℕ0  ∧  𝐴  ∈  ( ℤ≥ ‘ 2 )  ∧  𝑏  ≤  ( 𝐴  Yrm  𝑏 ) )  →  1  ∈  ℝ ) | 
						
							| 37 |  | simp3 | ⊢ ( ( 𝑏  ∈  ℕ0  ∧  𝐴  ∈  ( ℤ≥ ‘ 2 )  ∧  𝑏  ≤  ( 𝐴  Yrm  𝑏 ) )  →  𝑏  ≤  ( 𝐴  Yrm  𝑏 ) ) | 
						
							| 38 | 34 35 36 37 | leadd1dd | ⊢ ( ( 𝑏  ∈  ℕ0  ∧  𝐴  ∈  ( ℤ≥ ‘ 2 )  ∧  𝑏  ≤  ( 𝐴  Yrm  𝑏 ) )  →  ( 𝑏  +  1 )  ≤  ( ( 𝐴  Yrm  𝑏 )  +  1 ) ) | 
						
							| 39 | 34 | ltp1d | ⊢ ( ( 𝑏  ∈  ℕ0  ∧  𝐴  ∈  ( ℤ≥ ‘ 2 )  ∧  𝑏  ≤  ( 𝐴  Yrm  𝑏 ) )  →  𝑏  <  ( 𝑏  +  1 ) ) | 
						
							| 40 |  | ltrmy | ⊢ ( ( 𝐴  ∈  ( ℤ≥ ‘ 2 )  ∧  𝑏  ∈  ℤ  ∧  ( 𝑏  +  1 )  ∈  ℤ )  →  ( 𝑏  <  ( 𝑏  +  1 )  ↔  ( 𝐴  Yrm  𝑏 )  <  ( 𝐴  Yrm  ( 𝑏  +  1 ) ) ) ) | 
						
							| 41 | 24 21 22 40 | syl3anc | ⊢ ( ( 𝑏  ∈  ℕ0  ∧  𝐴  ∈  ( ℤ≥ ‘ 2 )  ∧  𝑏  ≤  ( 𝐴  Yrm  𝑏 ) )  →  ( 𝑏  <  ( 𝑏  +  1 )  ↔  ( 𝐴  Yrm  𝑏 )  <  ( 𝐴  Yrm  ( 𝑏  +  1 ) ) ) ) | 
						
							| 42 | 39 41 | mpbid | ⊢ ( ( 𝑏  ∈  ℕ0  ∧  𝐴  ∈  ( ℤ≥ ‘ 2 )  ∧  𝑏  ≤  ( 𝐴  Yrm  𝑏 ) )  →  ( 𝐴  Yrm  𝑏 )  <  ( 𝐴  Yrm  ( 𝑏  +  1 ) ) ) | 
						
							| 43 |  | zltp1le | ⊢ ( ( ( 𝐴  Yrm  𝑏 )  ∈  ℤ  ∧  ( 𝐴  Yrm  ( 𝑏  +  1 ) )  ∈  ℤ )  →  ( ( 𝐴  Yrm  𝑏 )  <  ( 𝐴  Yrm  ( 𝑏  +  1 ) )  ↔  ( ( 𝐴  Yrm  𝑏 )  +  1 )  ≤  ( 𝐴  Yrm  ( 𝑏  +  1 ) ) ) ) | 
						
							| 44 | 27 31 43 | syl2anc | ⊢ ( ( 𝑏  ∈  ℕ0  ∧  𝐴  ∈  ( ℤ≥ ‘ 2 )  ∧  𝑏  ≤  ( 𝐴  Yrm  𝑏 ) )  →  ( ( 𝐴  Yrm  𝑏 )  <  ( 𝐴  Yrm  ( 𝑏  +  1 ) )  ↔  ( ( 𝐴  Yrm  𝑏 )  +  1 )  ≤  ( 𝐴  Yrm  ( 𝑏  +  1 ) ) ) ) | 
						
							| 45 | 42 44 | mpbid | ⊢ ( ( 𝑏  ∈  ℕ0  ∧  𝐴  ∈  ( ℤ≥ ‘ 2 )  ∧  𝑏  ≤  ( 𝐴  Yrm  𝑏 ) )  →  ( ( 𝐴  Yrm  𝑏 )  +  1 )  ≤  ( 𝐴  Yrm  ( 𝑏  +  1 ) ) ) | 
						
							| 46 | 23 29 32 38 45 | letrd | ⊢ ( ( 𝑏  ∈  ℕ0  ∧  𝐴  ∈  ( ℤ≥ ‘ 2 )  ∧  𝑏  ≤  ( 𝐴  Yrm  𝑏 ) )  →  ( 𝑏  +  1 )  ≤  ( 𝐴  Yrm  ( 𝑏  +  1 ) ) ) | 
						
							| 47 | 46 | 3exp | ⊢ ( 𝑏  ∈  ℕ0  →  ( 𝐴  ∈  ( ℤ≥ ‘ 2 )  →  ( 𝑏  ≤  ( 𝐴  Yrm  𝑏 )  →  ( 𝑏  +  1 )  ≤  ( 𝐴  Yrm  ( 𝑏  +  1 ) ) ) ) ) | 
						
							| 48 | 47 | a2d | ⊢ ( 𝑏  ∈  ℕ0  →  ( ( 𝐴  ∈  ( ℤ≥ ‘ 2 )  →  𝑏  ≤  ( 𝐴  Yrm  𝑏 ) )  →  ( 𝐴  ∈  ( ℤ≥ ‘ 2 )  →  ( 𝑏  +  1 )  ≤  ( 𝐴  Yrm  ( 𝑏  +  1 ) ) ) ) ) | 
						
							| 49 | 4 8 12 16 19 48 | nn0ind | ⊢ ( 𝑁  ∈  ℕ0  →  ( 𝐴  ∈  ( ℤ≥ ‘ 2 )  →  𝑁  ≤  ( 𝐴  Yrm  𝑁 ) ) ) | 
						
							| 50 | 49 | impcom | ⊢ ( ( 𝐴  ∈  ( ℤ≥ ‘ 2 )  ∧  𝑁  ∈  ℕ0 )  →  𝑁  ≤  ( 𝐴  Yrm  𝑁 ) ) |