| Step | Hyp | Ref | Expression | 
						
							| 1 |  | 1st2nd2 |  | 
						
							| 2 | 1 | ad2antll |  | 
						
							| 3 |  | simprl |  | 
						
							| 4 | 2 3 | eqeltrrd |  | 
						
							| 5 |  | fvex |  | 
						
							| 6 |  | fvex |  | 
						
							| 7 | 5 6 | opelrn |  | 
						
							| 8 | 4 7 | syl |  | 
						
							| 9 |  | pwuninel |  | 
						
							| 10 |  | xp2nd |  | 
						
							| 11 | 10 | ad2antll |  | 
						
							| 12 |  | elsni |  | 
						
							| 13 | 11 12 | syl |  | 
						
							| 14 | 13 | eleq1d |  | 
						
							| 15 | 9 14 | mtbiri |  | 
						
							| 16 | 8 15 | pm2.65da |  | 
						
							| 17 |  | elin |  | 
						
							| 18 | 16 17 | sylnibr |  | 
						
							| 19 | 18 | eq0rdv |  | 
						
							| 20 |  | simpr |  | 
						
							| 21 |  | rnexg |  | 
						
							| 22 | 21 | adantr |  | 
						
							| 23 |  | uniexg |  | 
						
							| 24 |  | pwexg |  | 
						
							| 25 | 22 23 24 | 3syl |  | 
						
							| 26 |  | xpsneng |  | 
						
							| 27 | 20 25 26 | syl2anc |  | 
						
							| 28 | 19 27 | jca |  |