| Step | Hyp | Ref | Expression | 
						
							| 1 |  | dvdslelem.1 | ⊢ 𝑀  ∈  ℤ | 
						
							| 2 |  | dvdslelem.2 | ⊢ 𝑁  ∈  ℕ | 
						
							| 3 |  | dvdslelem.3 | ⊢ 𝐾  ∈  ℤ | 
						
							| 4 | 3 | zrei | ⊢ 𝐾  ∈  ℝ | 
						
							| 5 |  | 0re | ⊢ 0  ∈  ℝ | 
						
							| 6 |  | lelttric | ⊢ ( ( 𝐾  ∈  ℝ  ∧  0  ∈  ℝ )  →  ( 𝐾  ≤  0  ∨  0  <  𝐾 ) ) | 
						
							| 7 | 4 5 6 | mp2an | ⊢ ( 𝐾  ≤  0  ∨  0  <  𝐾 ) | 
						
							| 8 |  | zgt0ge1 | ⊢ ( 𝐾  ∈  ℤ  →  ( 0  <  𝐾  ↔  1  ≤  𝐾 ) ) | 
						
							| 9 | 3 8 | ax-mp | ⊢ ( 0  <  𝐾  ↔  1  ≤  𝐾 ) | 
						
							| 10 | 9 | orbi2i | ⊢ ( ( 𝐾  ≤  0  ∨  0  <  𝐾 )  ↔  ( 𝐾  ≤  0  ∨  1  ≤  𝐾 ) ) | 
						
							| 11 | 7 10 | mpbi | ⊢ ( 𝐾  ≤  0  ∨  1  ≤  𝐾 ) | 
						
							| 12 |  | le0neg1 | ⊢ ( 𝐾  ∈  ℝ  →  ( 𝐾  ≤  0  ↔  0  ≤  - 𝐾 ) ) | 
						
							| 13 | 4 12 | ax-mp | ⊢ ( 𝐾  ≤  0  ↔  0  ≤  - 𝐾 ) | 
						
							| 14 | 2 | nngt0i | ⊢ 0  <  𝑁 | 
						
							| 15 | 2 | nnrei | ⊢ 𝑁  ∈  ℝ | 
						
							| 16 | 1 | zrei | ⊢ 𝑀  ∈  ℝ | 
						
							| 17 | 5 15 16 | lttri | ⊢ ( ( 0  <  𝑁  ∧  𝑁  <  𝑀 )  →  0  <  𝑀 ) | 
						
							| 18 | 14 17 | mpan | ⊢ ( 𝑁  <  𝑀  →  0  <  𝑀 ) | 
						
							| 19 | 5 16 | ltlei | ⊢ ( 0  <  𝑀  →  0  ≤  𝑀 ) | 
						
							| 20 | 18 19 | syl | ⊢ ( 𝑁  <  𝑀  →  0  ≤  𝑀 ) | 
						
							| 21 | 4 | renegcli | ⊢ - 𝐾  ∈  ℝ | 
						
							| 22 | 21 16 | mulge0i | ⊢ ( ( 0  ≤  - 𝐾  ∧  0  ≤  𝑀 )  →  0  ≤  ( - 𝐾  ·  𝑀 ) ) | 
						
							| 23 | 20 22 | sylan2 | ⊢ ( ( 0  ≤  - 𝐾  ∧  𝑁  <  𝑀 )  →  0  ≤  ( - 𝐾  ·  𝑀 ) ) | 
						
							| 24 | 13 23 | sylanb | ⊢ ( ( 𝐾  ≤  0  ∧  𝑁  <  𝑀 )  →  0  ≤  ( - 𝐾  ·  𝑀 ) ) | 
						
							| 25 | 24 | expcom | ⊢ ( 𝑁  <  𝑀  →  ( 𝐾  ≤  0  →  0  ≤  ( - 𝐾  ·  𝑀 ) ) ) | 
						
							| 26 | 4 16 | remulcli | ⊢ ( 𝐾  ·  𝑀 )  ∈  ℝ | 
						
							| 27 |  | le0neg1 | ⊢ ( ( 𝐾  ·  𝑀 )  ∈  ℝ  →  ( ( 𝐾  ·  𝑀 )  ≤  0  ↔  0  ≤  - ( 𝐾  ·  𝑀 ) ) ) | 
						
							| 28 | 26 27 | ax-mp | ⊢ ( ( 𝐾  ·  𝑀 )  ≤  0  ↔  0  ≤  - ( 𝐾  ·  𝑀 ) ) | 
						
							| 29 | 4 | recni | ⊢ 𝐾  ∈  ℂ | 
						
							| 30 | 16 | recni | ⊢ 𝑀  ∈  ℂ | 
						
							| 31 | 29 30 | mulneg1i | ⊢ ( - 𝐾  ·  𝑀 )  =  - ( 𝐾  ·  𝑀 ) | 
						
							| 32 | 31 | breq2i | ⊢ ( 0  ≤  ( - 𝐾  ·  𝑀 )  ↔  0  ≤  - ( 𝐾  ·  𝑀 ) ) | 
						
							| 33 | 28 32 | bitr4i | ⊢ ( ( 𝐾  ·  𝑀 )  ≤  0  ↔  0  ≤  ( - 𝐾  ·  𝑀 ) ) | 
						
							| 34 | 25 33 | imbitrrdi | ⊢ ( 𝑁  <  𝑀  →  ( 𝐾  ≤  0  →  ( 𝐾  ·  𝑀 )  ≤  0 ) ) | 
						
							| 35 | 26 5 15 | lelttri | ⊢ ( ( ( 𝐾  ·  𝑀 )  ≤  0  ∧  0  <  𝑁 )  →  ( 𝐾  ·  𝑀 )  <  𝑁 ) | 
						
							| 36 | 14 35 | mpan2 | ⊢ ( ( 𝐾  ·  𝑀 )  ≤  0  →  ( 𝐾  ·  𝑀 )  <  𝑁 ) | 
						
							| 37 | 34 36 | syl6 | ⊢ ( 𝑁  <  𝑀  →  ( 𝐾  ≤  0  →  ( 𝐾  ·  𝑀 )  <  𝑁 ) ) | 
						
							| 38 |  | lemulge12 | ⊢ ( ( ( 𝑀  ∈  ℝ  ∧  𝐾  ∈  ℝ )  ∧  ( 0  ≤  𝑀  ∧  1  ≤  𝐾 ) )  →  𝑀  ≤  ( 𝐾  ·  𝑀 ) ) | 
						
							| 39 | 16 4 38 | mpanl12 | ⊢ ( ( 0  ≤  𝑀  ∧  1  ≤  𝐾 )  →  𝑀  ≤  ( 𝐾  ·  𝑀 ) ) | 
						
							| 40 | 20 39 | sylan | ⊢ ( ( 𝑁  <  𝑀  ∧  1  ≤  𝐾 )  →  𝑀  ≤  ( 𝐾  ·  𝑀 ) ) | 
						
							| 41 | 40 | ex | ⊢ ( 𝑁  <  𝑀  →  ( 1  ≤  𝐾  →  𝑀  ≤  ( 𝐾  ·  𝑀 ) ) ) | 
						
							| 42 | 15 16 26 | ltletri | ⊢ ( ( 𝑁  <  𝑀  ∧  𝑀  ≤  ( 𝐾  ·  𝑀 ) )  →  𝑁  <  ( 𝐾  ·  𝑀 ) ) | 
						
							| 43 | 42 | ex | ⊢ ( 𝑁  <  𝑀  →  ( 𝑀  ≤  ( 𝐾  ·  𝑀 )  →  𝑁  <  ( 𝐾  ·  𝑀 ) ) ) | 
						
							| 44 | 41 43 | syld | ⊢ ( 𝑁  <  𝑀  →  ( 1  ≤  𝐾  →  𝑁  <  ( 𝐾  ·  𝑀 ) ) ) | 
						
							| 45 | 37 44 | orim12d | ⊢ ( 𝑁  <  𝑀  →  ( ( 𝐾  ≤  0  ∨  1  ≤  𝐾 )  →  ( ( 𝐾  ·  𝑀 )  <  𝑁  ∨  𝑁  <  ( 𝐾  ·  𝑀 ) ) ) ) | 
						
							| 46 | 11 45 | mpi | ⊢ ( 𝑁  <  𝑀  →  ( ( 𝐾  ·  𝑀 )  <  𝑁  ∨  𝑁  <  ( 𝐾  ·  𝑀 ) ) ) | 
						
							| 47 | 26 15 | lttri2i | ⊢ ( ( 𝐾  ·  𝑀 )  ≠  𝑁  ↔  ( ( 𝐾  ·  𝑀 )  <  𝑁  ∨  𝑁  <  ( 𝐾  ·  𝑀 ) ) ) | 
						
							| 48 | 46 47 | sylibr | ⊢ ( 𝑁  <  𝑀  →  ( 𝐾  ·  𝑀 )  ≠  𝑁 ) |