| Step | Hyp | Ref | Expression | 
						
							| 1 |  | psgnval.g |  | 
						
							| 2 |  | psgnval.t |  | 
						
							| 3 |  | psgnval.n |  | 
						
							| 4 |  | eqid |  | 
						
							| 5 |  | eqid |  | 
						
							| 6 | 1 4 5 3 | psgnfn |  | 
						
							| 7 | 6 | fndmi |  | 
						
							| 8 |  | eqid |  | 
						
							| 9 | 2 1 4 8 | symggen |  | 
						
							| 10 | 1 | symggrp |  | 
						
							| 11 | 10 | grpmndd |  | 
						
							| 12 | 2 1 4 | symgtrf |  | 
						
							| 13 | 4 8 | gsumwspan |  | 
						
							| 14 | 11 12 13 | sylancl |  | 
						
							| 15 | 9 14 | eqtr3d |  | 
						
							| 16 | 7 15 | eqtrid |  | 
						
							| 17 | 16 | eleq2d |  | 
						
							| 18 |  | eqid |  | 
						
							| 19 |  | ovex |  | 
						
							| 20 | 18 19 | elrnmpti |  | 
						
							| 21 | 17 20 | bitrdi |  |