| Step | Hyp | Ref | Expression | 
						
							| 1 |  | 19.28v |  | 
						
							| 2 |  | r19.42v |  | 
						
							| 3 |  | 19.26 |  | 
						
							| 4 |  | 19.26 |  | 
						
							| 5 |  | jcab |  | 
						
							| 6 | 5 | albii |  | 
						
							| 7 |  | pwss |  | 
						
							| 8 |  | pwss |  | 
						
							| 9 | 7 8 | anbi12i |  | 
						
							| 10 | 4 6 9 | 3bitr4i |  | 
						
							| 11 |  | ralcom4 |  | 
						
							| 12 |  | 19.23v |  | 
						
							| 13 |  | 3anass |  | 
						
							| 14 | 13 | exbii |  | 
						
							| 15 |  | df-rex |  | 
						
							| 16 | 14 15 | bitr4i |  | 
						
							| 17 | 16 | imbi1i |  | 
						
							| 18 | 12 17 | bitri |  | 
						
							| 19 | 18 | ralbii |  | 
						
							| 20 | 11 19 | bitr3i |  | 
						
							| 21 | 10 20 | anbi12i |  | 
						
							| 22 |  | anass |  | 
						
							| 23 | 21 22 | bitri |  | 
						
							| 24 | 3 23 | bitri |  | 
						
							| 25 |  | df-ss |  | 
						
							| 26 |  | df-an |  | 
						
							| 27 | 25 26 | imbi12i |  | 
						
							| 28 |  | 3impexp |  | 
						
							| 29 |  | biid |  | 
						
							| 30 |  | expanduniss |  | 
						
							| 31 | 29 30 | expandan |  | 
						
							| 32 | 31 | expandrexn |  | 
						
							| 33 | 32 | imbi2i |  | 
						
							| 34 | 33 | imbi2i |  | 
						
							| 35 | 34 | imbi2i |  | 
						
							| 36 | 28 35 | bitri |  | 
						
							| 37 | 36 | expandral |  | 
						
							| 38 | 27 37 | expandan |  | 
						
							| 39 | 38 | albii |  | 
						
							| 40 | 24 39 | bitr3i |  | 
						
							| 41 | 40 | expandrex |  | 
						
							| 42 | 2 41 | bitr3i |  | 
						
							| 43 | 42 | albii |  | 
						
							| 44 | 1 43 | bitr3i |  | 
						
							| 45 | 44 | expandral |  |