| Step | Hyp | Ref | Expression | 
						
							| 1 |  | xrge0cmn |  | 
						
							| 2 |  | cmnmnd |  | 
						
							| 3 | 1 2 | ax-mp |  | 
						
							| 4 |  | ovex |  | 
						
							| 5 |  | xrge0base |  | 
						
							| 6 |  | xrge0le |  | 
						
							| 7 |  | eliccxr |  | 
						
							| 8 | 7 | xrleidd |  | 
						
							| 9 |  | eliccxr |  | 
						
							| 10 |  | xrletri3 |  | 
						
							| 11 | 10 | biimprd |  | 
						
							| 12 | 7 9 11 | syl2an |  | 
						
							| 13 |  | eliccxr |  | 
						
							| 14 |  | xrletr |  | 
						
							| 15 | 7 9 13 14 | syl3an |  | 
						
							| 16 | 4 5 6 8 12 15 | isposi |  | 
						
							| 17 |  | xrletri |  | 
						
							| 18 | 7 9 17 | syl2an |  | 
						
							| 19 | 18 | rgen2 |  | 
						
							| 20 | 5 6 | istos |  | 
						
							| 21 | 16 19 20 | mpbir2an |  | 
						
							| 22 |  | xleadd1a |  | 
						
							| 23 | 22 | ex |  | 
						
							| 24 | 7 9 13 23 | syl3an |  | 
						
							| 25 | 24 | rgen3 |  | 
						
							| 26 |  | xrge0plusg |  | 
						
							| 27 | 5 26 6 | isomnd |  | 
						
							| 28 | 3 21 25 27 | mpbir3an |  |