| Step | Hyp | Ref | Expression | 
						
							| 1 |  | elmapintrab.ex |  | 
						
							| 2 |  | elmapintrab.sub |  | 
						
							| 3 |  | elintrabg |  | 
						
							| 4 |  | df-ral |  | 
						
							| 5 | 3 4 | bitrdi |  | 
						
							| 6 |  | velpw |  | 
						
							| 7 |  | 19.23v |  | 
						
							| 8 | 7 | bicomi |  | 
						
							| 9 | 6 8 | imbi12i |  | 
						
							| 10 |  | 19.21v |  | 
						
							| 11 |  | bi2.04 |  | 
						
							| 12 |  | impexp |  | 
						
							| 13 | 11 12 | bitri |  | 
						
							| 14 | 13 | albii |  | 
						
							| 15 | 9 10 14 | 3bitr2i |  | 
						
							| 16 | 15 | albii |  | 
						
							| 17 |  | alcom |  | 
						
							| 18 |  | sseq1 |  | 
						
							| 19 |  | eleq2 |  | 
						
							| 20 | 2 | sseli |  | 
						
							| 21 | 20 | pm4.71ri |  | 
						
							| 22 | 19 21 | bitrdi |  | 
						
							| 23 | 18 22 | imbi12d |  | 
						
							| 24 | 23 | imbi2d |  | 
						
							| 25 | 1 24 | ceqsalv |  | 
						
							| 26 |  | bi2.04 |  | 
						
							| 27 |  | pm5.5 |  | 
						
							| 28 | 2 27 | ax-mp |  | 
						
							| 29 |  | jcab |  | 
						
							| 30 | 28 29 | bitri |  | 
						
							| 31 | 25 26 30 | 3bitri |  | 
						
							| 32 | 31 | albii |  | 
						
							| 33 |  | 19.26 |  | 
						
							| 34 |  | 19.23v |  | 
						
							| 35 | 34 | anbi1i |  | 
						
							| 36 | 32 33 35 | 3bitri |  | 
						
							| 37 | 16 17 36 | 3bitri |  | 
						
							| 38 | 5 37 | bitrdi |  |