| Step | Hyp | Ref | Expression | 
						
							| 1 |  | harcl |  | 
						
							| 2 |  | sdomdom |  | 
						
							| 3 |  | ondomen |  | 
						
							| 4 | 1 2 3 | sylancr |  | 
						
							| 5 |  | onenon |  | 
						
							| 6 | 1 5 | ax-mp |  | 
						
							| 7 |  | cardsdom2 |  | 
						
							| 8 | 4 6 7 | sylancl |  | 
						
							| 9 | 8 | ibir |  | 
						
							| 10 |  | harcard |  | 
						
							| 11 | 9 10 | eleqtrdi |  | 
						
							| 12 |  | elharval |  | 
						
							| 13 | 12 | simprbi |  | 
						
							| 14 | 11 13 | syl |  | 
						
							| 15 |  | cardid2 |  | 
						
							| 16 |  | domen1 |  | 
						
							| 17 | 4 15 16 | 3syl |  | 
						
							| 18 | 14 17 | mpbid |  | 
						
							| 19 |  | domnsym |  | 
						
							| 20 | 18 19 | syl |  | 
						
							| 21 | 20 | con2i |  | 
						
							| 22 |  | sdomen2 |  | 
						
							| 23 | 22 | notbid |  | 
						
							| 24 | 21 23 | imbitrid |  | 
						
							| 25 |  | imnan |  | 
						
							| 26 | 24 25 | sylib |  | 
						
							| 27 | 26 | alrimiv |  | 
						
							| 28 | 27 | olcd |  | 
						
							| 29 |  | relen |  | 
						
							| 30 | 29 | brrelex2i |  | 
						
							| 31 |  | pwexb |  | 
						
							| 32 | 30 31 | sylibr |  | 
						
							| 33 |  | elgch |  | 
						
							| 34 | 32 33 | syl |  | 
						
							| 35 | 28 34 | mpbird |  |