| Step | Hyp | Ref | Expression | 
						
							| 1 |  | pell14qrss1234 |  | 
						
							| 2 | 1 | sselda |  | 
						
							| 3 |  | pell14qrgt0 |  | 
						
							| 4 | 2 3 | jca |  | 
						
							| 5 |  | 0re |  | 
						
							| 6 |  | pell1234qrre |  | 
						
							| 7 |  | ltnsym |  | 
						
							| 8 | 5 6 7 | sylancr |  | 
						
							| 9 | 8 | impr |  | 
						
							| 10 | 6 | adantrr |  | 
						
							| 11 | 10 | lt0neg1d |  | 
						
							| 12 | 9 11 | mtbid |  | 
						
							| 13 |  | pell14qrgt0 |  | 
						
							| 14 | 13 | ex |  | 
						
							| 15 | 14 | adantr |  | 
						
							| 16 | 12 15 | mtod |  | 
						
							| 17 |  | pell1234qrdich |  | 
						
							| 18 | 17 | adantrr |  | 
						
							| 19 |  | orel2 |  | 
						
							| 20 | 16 18 19 | sylc |  | 
						
							| 21 | 4 20 | impbida |  |