| Step | Hyp | Ref | Expression | 
						
							| 1 |  | prdsgrpd.y |  | 
						
							| 2 |  | prdsgrpd.i |  | 
						
							| 3 |  | prdsgrpd.s |  | 
						
							| 4 |  | prdsgrpd.r |  | 
						
							| 5 |  | prdsinvgd.b |  | 
						
							| 6 |  | prdsinvgd.n |  | 
						
							| 7 |  | prdsinvgd.x |  | 
						
							| 8 |  | eqid |  | 
						
							| 9 | 3 | elexd |  | 
						
							| 10 | 2 | elexd |  | 
						
							| 11 |  | eqid |  | 
						
							| 12 |  | eqid |  | 
						
							| 13 | 1 5 8 9 10 4 7 11 12 | prdsinvlem |  | 
						
							| 14 | 13 | simprd |  | 
						
							| 15 |  | grpmnd |  | 
						
							| 16 | 15 | ssriv |  | 
						
							| 17 |  | fss |  | 
						
							| 18 | 4 16 17 | sylancl |  | 
						
							| 19 | 1 2 3 18 | prds0g |  | 
						
							| 20 | 14 19 | eqtrd |  | 
						
							| 21 | 1 2 3 4 | prdsgrpd |  | 
						
							| 22 | 13 | simpld |  | 
						
							| 23 |  | eqid |  | 
						
							| 24 | 5 8 23 6 | grpinvid2 |  | 
						
							| 25 | 21 7 22 24 | syl3anc |  | 
						
							| 26 | 20 25 | mpbird |  |