| Step | Hyp | Ref | Expression | 
						
							| 1 |  | opex |  | 
						
							| 2 |  | setsvalg |  | 
						
							| 3 | 1 2 | mpan2 |  | 
						
							| 4 | 3 | reseq1d |  | 
						
							| 5 |  | resundir |  | 
						
							| 6 |  | dmsnopss |  | 
						
							| 7 |  | sscon |  | 
						
							| 8 | 6 7 | ax-mp |  | 
						
							| 9 |  | resabs1 |  | 
						
							| 10 | 8 9 | ax-mp |  | 
						
							| 11 |  | dmres |  | 
						
							| 12 |  | disj2 |  | 
						
							| 13 | 8 12 | mpbir |  | 
						
							| 14 | 11 13 | eqtri |  | 
						
							| 15 |  | relres |  | 
						
							| 16 |  | reldm0 |  | 
						
							| 17 | 15 16 | ax-mp |  | 
						
							| 18 | 14 17 | mpbir |  | 
						
							| 19 | 10 18 | uneq12i |  | 
						
							| 20 |  | un0 |  | 
						
							| 21 | 19 20 | eqtri |  | 
						
							| 22 | 5 21 | eqtri |  | 
						
							| 23 | 4 22 | eqtrdi |  |