| Step | Hyp | Ref | Expression | 
						
							| 1 |  | sn-negex |  | 
						
							| 2 | 1 | adantr |  | 
						
							| 3 |  | simprl |  | 
						
							| 4 |  | simplr |  | 
						
							| 5 | 3 4 | addcld |  | 
						
							| 6 |  | simplrr |  | 
						
							| 7 | 6 | oveq1d |  | 
						
							| 8 |  | simplll |  | 
						
							| 9 |  | simplrl |  | 
						
							| 10 |  | simpllr |  | 
						
							| 11 | 8 9 10 | addassd |  | 
						
							| 12 |  | sn-addlid |  | 
						
							| 13 | 10 12 | syl |  | 
						
							| 14 | 7 11 13 | 3eqtr3rd |  | 
						
							| 15 | 14 | eqeq2d |  | 
						
							| 16 |  | simpr |  | 
						
							| 17 | 9 10 | addcld |  | 
						
							| 18 | 8 16 17 | sn-addcand |  | 
						
							| 19 | 15 18 | bitrd |  | 
						
							| 20 | 19 | ralrimiva |  | 
						
							| 21 |  | reu6i |  | 
						
							| 22 | 5 20 21 | syl2anc |  | 
						
							| 23 | 2 22 | rexlimddv |  |