| Step | Hyp | Ref | Expression | 
						
							| 1 |  | oveq2 | ⊢ ( 𝑥  =  𝑁  →  ( 𝐴  /L  𝑥 )  =  ( 𝐴  /L  𝑁 ) ) | 
						
							| 2 | 1 | oveq1d | ⊢ ( 𝑥  =  𝑁  →  ( ( 𝐴  /L  𝑥 )  ·  ( 𝐴  /L  0 ) )  =  ( ( 𝐴  /L  𝑁 )  ·  ( 𝐴  /L  0 ) ) ) | 
						
							| 3 | 2 | eqeq2d | ⊢ ( 𝑥  =  𝑁  →  ( ( 𝐴  /L  0 )  =  ( ( 𝐴  /L  𝑥 )  ·  ( 𝐴  /L  0 ) )  ↔  ( 𝐴  /L  0 )  =  ( ( 𝐴  /L  𝑁 )  ·  ( 𝐴  /L  0 ) ) ) ) | 
						
							| 4 |  | sq1 | ⊢ ( 1 ↑ 2 )  =  1 | 
						
							| 5 | 4 | eqeq2i | ⊢ ( ( 𝐴 ↑ 2 )  =  ( 1 ↑ 2 )  ↔  ( 𝐴 ↑ 2 )  =  1 ) | 
						
							| 6 |  | nn0re | ⊢ ( 𝐴  ∈  ℕ0  →  𝐴  ∈  ℝ ) | 
						
							| 7 |  | nn0ge0 | ⊢ ( 𝐴  ∈  ℕ0  →  0  ≤  𝐴 ) | 
						
							| 8 |  | 1re | ⊢ 1  ∈  ℝ | 
						
							| 9 |  | 0le1 | ⊢ 0  ≤  1 | 
						
							| 10 |  | sq11 | ⊢ ( ( ( 𝐴  ∈  ℝ  ∧  0  ≤  𝐴 )  ∧  ( 1  ∈  ℝ  ∧  0  ≤  1 ) )  →  ( ( 𝐴 ↑ 2 )  =  ( 1 ↑ 2 )  ↔  𝐴  =  1 ) ) | 
						
							| 11 | 8 9 10 | mpanr12 | ⊢ ( ( 𝐴  ∈  ℝ  ∧  0  ≤  𝐴 )  →  ( ( 𝐴 ↑ 2 )  =  ( 1 ↑ 2 )  ↔  𝐴  =  1 ) ) | 
						
							| 12 | 6 7 11 | syl2anc | ⊢ ( 𝐴  ∈  ℕ0  →  ( ( 𝐴 ↑ 2 )  =  ( 1 ↑ 2 )  ↔  𝐴  =  1 ) ) | 
						
							| 13 | 12 | adantr | ⊢ ( ( 𝐴  ∈  ℕ0  ∧  𝑥  ∈  ℤ )  →  ( ( 𝐴 ↑ 2 )  =  ( 1 ↑ 2 )  ↔  𝐴  =  1 ) ) | 
						
							| 14 | 5 13 | bitr3id | ⊢ ( ( 𝐴  ∈  ℕ0  ∧  𝑥  ∈  ℤ )  →  ( ( 𝐴 ↑ 2 )  =  1  ↔  𝐴  =  1 ) ) | 
						
							| 15 | 14 | biimpa | ⊢ ( ( ( 𝐴  ∈  ℕ0  ∧  𝑥  ∈  ℤ )  ∧  ( 𝐴 ↑ 2 )  =  1 )  →  𝐴  =  1 ) | 
						
							| 16 | 15 | oveq1d | ⊢ ( ( ( 𝐴  ∈  ℕ0  ∧  𝑥  ∈  ℤ )  ∧  ( 𝐴 ↑ 2 )  =  1 )  →  ( 𝐴  /L  𝑥 )  =  ( 1  /L  𝑥 ) ) | 
						
							| 17 |  | 1lgs | ⊢ ( 𝑥  ∈  ℤ  →  ( 1  /L  𝑥 )  =  1 ) | 
						
							| 18 | 17 | ad2antlr | ⊢ ( ( ( 𝐴  ∈  ℕ0  ∧  𝑥  ∈  ℤ )  ∧  ( 𝐴 ↑ 2 )  =  1 )  →  ( 1  /L  𝑥 )  =  1 ) | 
						
							| 19 | 16 18 | eqtrd | ⊢ ( ( ( 𝐴  ∈  ℕ0  ∧  𝑥  ∈  ℤ )  ∧  ( 𝐴 ↑ 2 )  =  1 )  →  ( 𝐴  /L  𝑥 )  =  1 ) | 
						
							| 20 | 19 | oveq1d | ⊢ ( ( ( 𝐴  ∈  ℕ0  ∧  𝑥  ∈  ℤ )  ∧  ( 𝐴 ↑ 2 )  =  1 )  →  ( ( 𝐴  /L  𝑥 )  ·  ( 𝐴  /L  0 ) )  =  ( 1  ·  ( 𝐴  /L  0 ) ) ) | 
						
							| 21 |  | nn0z | ⊢ ( 𝐴  ∈  ℕ0  →  𝐴  ∈  ℤ ) | 
						
							| 22 | 21 | ad2antrr | ⊢ ( ( ( 𝐴  ∈  ℕ0  ∧  𝑥  ∈  ℤ )  ∧  ( 𝐴 ↑ 2 )  =  1 )  →  𝐴  ∈  ℤ ) | 
						
							| 23 |  | 0z | ⊢ 0  ∈  ℤ | 
						
							| 24 |  | lgscl | ⊢ ( ( 𝐴  ∈  ℤ  ∧  0  ∈  ℤ )  →  ( 𝐴  /L  0 )  ∈  ℤ ) | 
						
							| 25 | 22 23 24 | sylancl | ⊢ ( ( ( 𝐴  ∈  ℕ0  ∧  𝑥  ∈  ℤ )  ∧  ( 𝐴 ↑ 2 )  =  1 )  →  ( 𝐴  /L  0 )  ∈  ℤ ) | 
						
							| 26 | 25 | zcnd | ⊢ ( ( ( 𝐴  ∈  ℕ0  ∧  𝑥  ∈  ℤ )  ∧  ( 𝐴 ↑ 2 )  =  1 )  →  ( 𝐴  /L  0 )  ∈  ℂ ) | 
						
							| 27 | 26 | mullidd | ⊢ ( ( ( 𝐴  ∈  ℕ0  ∧  𝑥  ∈  ℤ )  ∧  ( 𝐴 ↑ 2 )  =  1 )  →  ( 1  ·  ( 𝐴  /L  0 ) )  =  ( 𝐴  /L  0 ) ) | 
						
							| 28 | 20 27 | eqtr2d | ⊢ ( ( ( 𝐴  ∈  ℕ0  ∧  𝑥  ∈  ℤ )  ∧  ( 𝐴 ↑ 2 )  =  1 )  →  ( 𝐴  /L  0 )  =  ( ( 𝐴  /L  𝑥 )  ·  ( 𝐴  /L  0 ) ) ) | 
						
							| 29 |  | lgscl | ⊢ ( ( 𝐴  ∈  ℤ  ∧  𝑥  ∈  ℤ )  →  ( 𝐴  /L  𝑥 )  ∈  ℤ ) | 
						
							| 30 | 21 29 | sylan | ⊢ ( ( 𝐴  ∈  ℕ0  ∧  𝑥  ∈  ℤ )  →  ( 𝐴  /L  𝑥 )  ∈  ℤ ) | 
						
							| 31 | 30 | zcnd | ⊢ ( ( 𝐴  ∈  ℕ0  ∧  𝑥  ∈  ℤ )  →  ( 𝐴  /L  𝑥 )  ∈  ℂ ) | 
						
							| 32 | 31 | adantr | ⊢ ( ( ( 𝐴  ∈  ℕ0  ∧  𝑥  ∈  ℤ )  ∧  ( 𝐴 ↑ 2 )  ≠  1 )  →  ( 𝐴  /L  𝑥 )  ∈  ℂ ) | 
						
							| 33 | 32 | mul01d | ⊢ ( ( ( 𝐴  ∈  ℕ0  ∧  𝑥  ∈  ℤ )  ∧  ( 𝐴 ↑ 2 )  ≠  1 )  →  ( ( 𝐴  /L  𝑥 )  ·  0 )  =  0 ) | 
						
							| 34 | 21 | adantr | ⊢ ( ( 𝐴  ∈  ℕ0  ∧  𝑥  ∈  ℤ )  →  𝐴  ∈  ℤ ) | 
						
							| 35 |  | lgs0 | ⊢ ( 𝐴  ∈  ℤ  →  ( 𝐴  /L  0 )  =  if ( ( 𝐴 ↑ 2 )  =  1 ,  1 ,  0 ) ) | 
						
							| 36 | 34 35 | syl | ⊢ ( ( 𝐴  ∈  ℕ0  ∧  𝑥  ∈  ℤ )  →  ( 𝐴  /L  0 )  =  if ( ( 𝐴 ↑ 2 )  =  1 ,  1 ,  0 ) ) | 
						
							| 37 |  | ifnefalse | ⊢ ( ( 𝐴 ↑ 2 )  ≠  1  →  if ( ( 𝐴 ↑ 2 )  =  1 ,  1 ,  0 )  =  0 ) | 
						
							| 38 | 36 37 | sylan9eq | ⊢ ( ( ( 𝐴  ∈  ℕ0  ∧  𝑥  ∈  ℤ )  ∧  ( 𝐴 ↑ 2 )  ≠  1 )  →  ( 𝐴  /L  0 )  =  0 ) | 
						
							| 39 | 38 | oveq2d | ⊢ ( ( ( 𝐴  ∈  ℕ0  ∧  𝑥  ∈  ℤ )  ∧  ( 𝐴 ↑ 2 )  ≠  1 )  →  ( ( 𝐴  /L  𝑥 )  ·  ( 𝐴  /L  0 ) )  =  ( ( 𝐴  /L  𝑥 )  ·  0 ) ) | 
						
							| 40 | 33 39 38 | 3eqtr4rd | ⊢ ( ( ( 𝐴  ∈  ℕ0  ∧  𝑥  ∈  ℤ )  ∧  ( 𝐴 ↑ 2 )  ≠  1 )  →  ( 𝐴  /L  0 )  =  ( ( 𝐴  /L  𝑥 )  ·  ( 𝐴  /L  0 ) ) ) | 
						
							| 41 | 28 40 | pm2.61dane | ⊢ ( ( 𝐴  ∈  ℕ0  ∧  𝑥  ∈  ℤ )  →  ( 𝐴  /L  0 )  =  ( ( 𝐴  /L  𝑥 )  ·  ( 𝐴  /L  0 ) ) ) | 
						
							| 42 | 41 | ralrimiva | ⊢ ( 𝐴  ∈  ℕ0  →  ∀ 𝑥  ∈  ℤ ( 𝐴  /L  0 )  =  ( ( 𝐴  /L  𝑥 )  ·  ( 𝐴  /L  0 ) ) ) | 
						
							| 43 | 42 | 3ad2ant1 | ⊢ ( ( 𝐴  ∈  ℕ0  ∧  𝑀  ∈  ℤ  ∧  𝑁  ∈  ℤ )  →  ∀ 𝑥  ∈  ℤ ( 𝐴  /L  0 )  =  ( ( 𝐴  /L  𝑥 )  ·  ( 𝐴  /L  0 ) ) ) | 
						
							| 44 |  | simp3 | ⊢ ( ( 𝐴  ∈  ℕ0  ∧  𝑀  ∈  ℤ  ∧  𝑁  ∈  ℤ )  →  𝑁  ∈  ℤ ) | 
						
							| 45 | 3 43 44 | rspcdva | ⊢ ( ( 𝐴  ∈  ℕ0  ∧  𝑀  ∈  ℤ  ∧  𝑁  ∈  ℤ )  →  ( 𝐴  /L  0 )  =  ( ( 𝐴  /L  𝑁 )  ·  ( 𝐴  /L  0 ) ) ) | 
						
							| 46 | 45 | adantr | ⊢ ( ( ( 𝐴  ∈  ℕ0  ∧  𝑀  ∈  ℤ  ∧  𝑁  ∈  ℤ )  ∧  𝑀  =  0 )  →  ( 𝐴  /L  0 )  =  ( ( 𝐴  /L  𝑁 )  ·  ( 𝐴  /L  0 ) ) ) | 
						
							| 47 | 21 | 3ad2ant1 | ⊢ ( ( 𝐴  ∈  ℕ0  ∧  𝑀  ∈  ℤ  ∧  𝑁  ∈  ℤ )  →  𝐴  ∈  ℤ ) | 
						
							| 48 | 47 23 24 | sylancl | ⊢ ( ( 𝐴  ∈  ℕ0  ∧  𝑀  ∈  ℤ  ∧  𝑁  ∈  ℤ )  →  ( 𝐴  /L  0 )  ∈  ℤ ) | 
						
							| 49 | 48 | zcnd | ⊢ ( ( 𝐴  ∈  ℕ0  ∧  𝑀  ∈  ℤ  ∧  𝑁  ∈  ℤ )  →  ( 𝐴  /L  0 )  ∈  ℂ ) | 
						
							| 50 | 49 | adantr | ⊢ ( ( ( 𝐴  ∈  ℕ0  ∧  𝑀  ∈  ℤ  ∧  𝑁  ∈  ℤ )  ∧  𝑀  =  0 )  →  ( 𝐴  /L  0 )  ∈  ℂ ) | 
						
							| 51 |  | lgscl | ⊢ ( ( 𝐴  ∈  ℤ  ∧  𝑁  ∈  ℤ )  →  ( 𝐴  /L  𝑁 )  ∈  ℤ ) | 
						
							| 52 | 47 44 51 | syl2anc | ⊢ ( ( 𝐴  ∈  ℕ0  ∧  𝑀  ∈  ℤ  ∧  𝑁  ∈  ℤ )  →  ( 𝐴  /L  𝑁 )  ∈  ℤ ) | 
						
							| 53 | 52 | zcnd | ⊢ ( ( 𝐴  ∈  ℕ0  ∧  𝑀  ∈  ℤ  ∧  𝑁  ∈  ℤ )  →  ( 𝐴  /L  𝑁 )  ∈  ℂ ) | 
						
							| 54 | 53 | adantr | ⊢ ( ( ( 𝐴  ∈  ℕ0  ∧  𝑀  ∈  ℤ  ∧  𝑁  ∈  ℤ )  ∧  𝑀  =  0 )  →  ( 𝐴  /L  𝑁 )  ∈  ℂ ) | 
						
							| 55 | 50 54 | mulcomd | ⊢ ( ( ( 𝐴  ∈  ℕ0  ∧  𝑀  ∈  ℤ  ∧  𝑁  ∈  ℤ )  ∧  𝑀  =  0 )  →  ( ( 𝐴  /L  0 )  ·  ( 𝐴  /L  𝑁 ) )  =  ( ( 𝐴  /L  𝑁 )  ·  ( 𝐴  /L  0 ) ) ) | 
						
							| 56 | 46 55 | eqtr4d | ⊢ ( ( ( 𝐴  ∈  ℕ0  ∧  𝑀  ∈  ℤ  ∧  𝑁  ∈  ℤ )  ∧  𝑀  =  0 )  →  ( 𝐴  /L  0 )  =  ( ( 𝐴  /L  0 )  ·  ( 𝐴  /L  𝑁 ) ) ) | 
						
							| 57 |  | oveq1 | ⊢ ( 𝑀  =  0  →  ( 𝑀  ·  𝑁 )  =  ( 0  ·  𝑁 ) ) | 
						
							| 58 | 44 | zcnd | ⊢ ( ( 𝐴  ∈  ℕ0  ∧  𝑀  ∈  ℤ  ∧  𝑁  ∈  ℤ )  →  𝑁  ∈  ℂ ) | 
						
							| 59 | 58 | mul02d | ⊢ ( ( 𝐴  ∈  ℕ0  ∧  𝑀  ∈  ℤ  ∧  𝑁  ∈  ℤ )  →  ( 0  ·  𝑁 )  =  0 ) | 
						
							| 60 | 57 59 | sylan9eqr | ⊢ ( ( ( 𝐴  ∈  ℕ0  ∧  𝑀  ∈  ℤ  ∧  𝑁  ∈  ℤ )  ∧  𝑀  =  0 )  →  ( 𝑀  ·  𝑁 )  =  0 ) | 
						
							| 61 | 60 | oveq2d | ⊢ ( ( ( 𝐴  ∈  ℕ0  ∧  𝑀  ∈  ℤ  ∧  𝑁  ∈  ℤ )  ∧  𝑀  =  0 )  →  ( 𝐴  /L  ( 𝑀  ·  𝑁 ) )  =  ( 𝐴  /L  0 ) ) | 
						
							| 62 |  | simpr | ⊢ ( ( ( 𝐴  ∈  ℕ0  ∧  𝑀  ∈  ℤ  ∧  𝑁  ∈  ℤ )  ∧  𝑀  =  0 )  →  𝑀  =  0 ) | 
						
							| 63 | 62 | oveq2d | ⊢ ( ( ( 𝐴  ∈  ℕ0  ∧  𝑀  ∈  ℤ  ∧  𝑁  ∈  ℤ )  ∧  𝑀  =  0 )  →  ( 𝐴  /L  𝑀 )  =  ( 𝐴  /L  0 ) ) | 
						
							| 64 | 63 | oveq1d | ⊢ ( ( ( 𝐴  ∈  ℕ0  ∧  𝑀  ∈  ℤ  ∧  𝑁  ∈  ℤ )  ∧  𝑀  =  0 )  →  ( ( 𝐴  /L  𝑀 )  ·  ( 𝐴  /L  𝑁 ) )  =  ( ( 𝐴  /L  0 )  ·  ( 𝐴  /L  𝑁 ) ) ) | 
						
							| 65 | 56 61 64 | 3eqtr4d | ⊢ ( ( ( 𝐴  ∈  ℕ0  ∧  𝑀  ∈  ℤ  ∧  𝑁  ∈  ℤ )  ∧  𝑀  =  0 )  →  ( 𝐴  /L  ( 𝑀  ·  𝑁 ) )  =  ( ( 𝐴  /L  𝑀 )  ·  ( 𝐴  /L  𝑁 ) ) ) | 
						
							| 66 |  | oveq2 | ⊢ ( 𝑥  =  𝑀  →  ( 𝐴  /L  𝑥 )  =  ( 𝐴  /L  𝑀 ) ) | 
						
							| 67 | 66 | oveq1d | ⊢ ( 𝑥  =  𝑀  →  ( ( 𝐴  /L  𝑥 )  ·  ( 𝐴  /L  0 ) )  =  ( ( 𝐴  /L  𝑀 )  ·  ( 𝐴  /L  0 ) ) ) | 
						
							| 68 | 67 | eqeq2d | ⊢ ( 𝑥  =  𝑀  →  ( ( 𝐴  /L  0 )  =  ( ( 𝐴  /L  𝑥 )  ·  ( 𝐴  /L  0 ) )  ↔  ( 𝐴  /L  0 )  =  ( ( 𝐴  /L  𝑀 )  ·  ( 𝐴  /L  0 ) ) ) ) | 
						
							| 69 |  | simp2 | ⊢ ( ( 𝐴  ∈  ℕ0  ∧  𝑀  ∈  ℤ  ∧  𝑁  ∈  ℤ )  →  𝑀  ∈  ℤ ) | 
						
							| 70 | 68 43 69 | rspcdva | ⊢ ( ( 𝐴  ∈  ℕ0  ∧  𝑀  ∈  ℤ  ∧  𝑁  ∈  ℤ )  →  ( 𝐴  /L  0 )  =  ( ( 𝐴  /L  𝑀 )  ·  ( 𝐴  /L  0 ) ) ) | 
						
							| 71 | 70 | adantr | ⊢ ( ( ( 𝐴  ∈  ℕ0  ∧  𝑀  ∈  ℤ  ∧  𝑁  ∈  ℤ )  ∧  𝑁  =  0 )  →  ( 𝐴  /L  0 )  =  ( ( 𝐴  /L  𝑀 )  ·  ( 𝐴  /L  0 ) ) ) | 
						
							| 72 |  | oveq2 | ⊢ ( 𝑁  =  0  →  ( 𝑀  ·  𝑁 )  =  ( 𝑀  ·  0 ) ) | 
						
							| 73 | 69 | zcnd | ⊢ ( ( 𝐴  ∈  ℕ0  ∧  𝑀  ∈  ℤ  ∧  𝑁  ∈  ℤ )  →  𝑀  ∈  ℂ ) | 
						
							| 74 | 73 | mul01d | ⊢ ( ( 𝐴  ∈  ℕ0  ∧  𝑀  ∈  ℤ  ∧  𝑁  ∈  ℤ )  →  ( 𝑀  ·  0 )  =  0 ) | 
						
							| 75 | 72 74 | sylan9eqr | ⊢ ( ( ( 𝐴  ∈  ℕ0  ∧  𝑀  ∈  ℤ  ∧  𝑁  ∈  ℤ )  ∧  𝑁  =  0 )  →  ( 𝑀  ·  𝑁 )  =  0 ) | 
						
							| 76 | 75 | oveq2d | ⊢ ( ( ( 𝐴  ∈  ℕ0  ∧  𝑀  ∈  ℤ  ∧  𝑁  ∈  ℤ )  ∧  𝑁  =  0 )  →  ( 𝐴  /L  ( 𝑀  ·  𝑁 ) )  =  ( 𝐴  /L  0 ) ) | 
						
							| 77 |  | simpr | ⊢ ( ( ( 𝐴  ∈  ℕ0  ∧  𝑀  ∈  ℤ  ∧  𝑁  ∈  ℤ )  ∧  𝑁  =  0 )  →  𝑁  =  0 ) | 
						
							| 78 | 77 | oveq2d | ⊢ ( ( ( 𝐴  ∈  ℕ0  ∧  𝑀  ∈  ℤ  ∧  𝑁  ∈  ℤ )  ∧  𝑁  =  0 )  →  ( 𝐴  /L  𝑁 )  =  ( 𝐴  /L  0 ) ) | 
						
							| 79 | 78 | oveq2d | ⊢ ( ( ( 𝐴  ∈  ℕ0  ∧  𝑀  ∈  ℤ  ∧  𝑁  ∈  ℤ )  ∧  𝑁  =  0 )  →  ( ( 𝐴  /L  𝑀 )  ·  ( 𝐴  /L  𝑁 ) )  =  ( ( 𝐴  /L  𝑀 )  ·  ( 𝐴  /L  0 ) ) ) | 
						
							| 80 | 71 76 79 | 3eqtr4d | ⊢ ( ( ( 𝐴  ∈  ℕ0  ∧  𝑀  ∈  ℤ  ∧  𝑁  ∈  ℤ )  ∧  𝑁  =  0 )  →  ( 𝐴  /L  ( 𝑀  ·  𝑁 ) )  =  ( ( 𝐴  /L  𝑀 )  ·  ( 𝐴  /L  𝑁 ) ) ) | 
						
							| 81 |  | lgsdi | ⊢ ( ( ( 𝐴  ∈  ℤ  ∧  𝑀  ∈  ℤ  ∧  𝑁  ∈  ℤ )  ∧  ( 𝑀  ≠  0  ∧  𝑁  ≠  0 ) )  →  ( 𝐴  /L  ( 𝑀  ·  𝑁 ) )  =  ( ( 𝐴  /L  𝑀 )  ·  ( 𝐴  /L  𝑁 ) ) ) | 
						
							| 82 | 21 81 | syl3anl1 | ⊢ ( ( ( 𝐴  ∈  ℕ0  ∧  𝑀  ∈  ℤ  ∧  𝑁  ∈  ℤ )  ∧  ( 𝑀  ≠  0  ∧  𝑁  ≠  0 ) )  →  ( 𝐴  /L  ( 𝑀  ·  𝑁 ) )  =  ( ( 𝐴  /L  𝑀 )  ·  ( 𝐴  /L  𝑁 ) ) ) | 
						
							| 83 | 65 80 82 | pm2.61da2ne | ⊢ ( ( 𝐴  ∈  ℕ0  ∧  𝑀  ∈  ℤ  ∧  𝑁  ∈  ℤ )  →  ( 𝐴  /L  ( 𝑀  ·  𝑁 ) )  =  ( ( 𝐴  /L  𝑀 )  ·  ( 𝐴  /L  𝑁 ) ) ) |