| Step | Hyp | Ref | Expression | 
						
							| 1 |  | df-inr |  | 
						
							| 2 |  | 1onn |  | 
						
							| 3 |  | snidg |  | 
						
							| 4 | 2 3 | ax-mp |  | 
						
							| 5 |  | opelxpi |  | 
						
							| 6 | 4 5 | mpan |  | 
						
							| 7 | 6 | adantl |  | 
						
							| 8 |  | fvexd |  | 
						
							| 9 |  | 1st2nd2 |  | 
						
							| 10 |  | xp1st |  | 
						
							| 11 |  | elsni |  | 
						
							| 12 | 10 11 | syl |  | 
						
							| 13 | 12 | opeq1d |  | 
						
							| 14 | 9 13 | eqtrd |  | 
						
							| 15 | 14 | eqeq2d |  | 
						
							| 16 |  | eqcom |  | 
						
							| 17 |  | eqid |  | 
						
							| 18 |  | 1oex |  | 
						
							| 19 |  | vex |  | 
						
							| 20 | 18 19 | opth |  | 
						
							| 21 | 17 20 | mpbiran |  | 
						
							| 22 | 15 16 21 | 3bitr3g |  | 
						
							| 23 | 22 | bicomd |  | 
						
							| 24 | 23 | ad2antll |  | 
						
							| 25 | 1 7 8 24 | f1o2d |  | 
						
							| 26 | 25 | mptru |  |