| Step | Hyp | Ref | Expression | 
						
							| 1 |  | psrgrp.s |  | 
						
							| 2 |  | psrgrp.i |  | 
						
							| 3 |  | psrgrp.r |  | 
						
							| 4 |  | psrnegcl.d |  | 
						
							| 5 |  | psrnegcl.i |  | 
						
							| 6 |  | psrnegcl.b |  | 
						
							| 7 |  | psrnegcl.z |  | 
						
							| 8 |  | eqid |  | 
						
							| 9 | 8 5 3 | grpinvf1o |  | 
						
							| 10 |  | f1of |  | 
						
							| 11 | 9 10 | syl |  | 
						
							| 12 | 1 8 4 6 7 | psrelbas |  | 
						
							| 13 |  | fco |  | 
						
							| 14 | 11 12 13 | syl2anc |  | 
						
							| 15 |  | fvex |  | 
						
							| 16 |  | ovex |  | 
						
							| 17 | 4 16 | rabex2 |  | 
						
							| 18 | 15 17 | elmap |  | 
						
							| 19 | 14 18 | sylibr |  | 
						
							| 20 | 1 8 4 6 2 | psrbas |  | 
						
							| 21 | 19 20 | eleqtrrd |  |