| Step | Hyp | Ref | Expression | 
						
							| 1 |  | simpl1 |  | 
						
							| 2 |  | zsubcl |  | 
						
							| 3 | 2 | 3adant1 |  | 
						
							| 4 | 3 | adantr |  | 
						
							| 5 |  | zsubcl |  | 
						
							| 6 | 5 | adantl |  | 
						
							| 7 |  | dvds2add |  | 
						
							| 8 | 1 4 6 7 | syl3anc |  | 
						
							| 9 | 8 | 3impia |  | 
						
							| 10 |  | simpl2 |  | 
						
							| 11 | 10 | zcnd |  | 
						
							| 12 |  | zcn |  | 
						
							| 13 | 12 | ad2antrl |  | 
						
							| 14 |  | simpl3 |  | 
						
							| 15 | 14 | zcnd |  | 
						
							| 16 |  | zcn |  | 
						
							| 17 | 16 | ad2antll |  | 
						
							| 18 | 11 13 15 17 | addsub4d |  | 
						
							| 19 | 18 | 3adant3 |  | 
						
							| 20 | 9 19 | breqtrrd |  |