| Step | Hyp | Ref | Expression | 
						
							| 1 |  | zrhpsgninv.p |  | 
						
							| 2 |  | zrhpsgninv.y |  | 
						
							| 3 |  | zrhpsgninv.s |  | 
						
							| 4 |  | eqid |  | 
						
							| 5 | 4 3 1 | psgninv |  | 
						
							| 6 | 5 | 3adant1 |  | 
						
							| 7 | 6 | fveq2d |  | 
						
							| 8 |  | eqid |  | 
						
							| 9 | 4 3 8 | psgnghm2 |  | 
						
							| 10 |  | eqid |  | 
						
							| 11 | 1 10 | ghmf |  | 
						
							| 12 | 9 11 | syl |  | 
						
							| 13 | 12 | 3ad2ant2 |  | 
						
							| 14 |  | eqid |  | 
						
							| 15 | 4 1 14 | symginv |  | 
						
							| 16 | 15 | 3ad2ant3 |  | 
						
							| 17 | 4 | symggrp |  | 
						
							| 18 | 17 | 3ad2ant2 |  | 
						
							| 19 |  | simp3 |  | 
						
							| 20 | 1 14 | grpinvcl |  | 
						
							| 21 | 18 19 20 | syl2anc |  | 
						
							| 22 | 16 21 | eqeltrrd |  | 
						
							| 23 |  | fvco3 |  | 
						
							| 24 | 13 22 23 | syl2anc |  | 
						
							| 25 |  | fvco3 |  | 
						
							| 26 | 13 19 25 | syl2anc |  | 
						
							| 27 | 7 24 26 | 3eqtr4d |  |