| Step | Hyp | Ref | Expression | 
						
							| 1 |  | ringlz.1 |  | 
						
							| 2 |  | ringlz.2 |  | 
						
							| 3 |  | ringlz.3 |  | 
						
							| 4 |  | ringlz.4 |  | 
						
							| 5 | 3 | rngogrpo |  | 
						
							| 6 | 2 1 | grpoidcl |  | 
						
							| 7 | 2 1 | grpolid |  | 
						
							| 8 | 5 6 7 | syl2anc2 |  | 
						
							| 9 | 8 | adantr |  | 
						
							| 10 | 9 | oveq2d |  | 
						
							| 11 |  | simpr |  | 
						
							| 12 | 3 2 1 | rngo0cl |  | 
						
							| 13 | 12 | adantr |  | 
						
							| 14 | 11 13 13 | 3jca |  | 
						
							| 15 | 3 4 2 | rngodi |  | 
						
							| 16 | 14 15 | syldan |  | 
						
							| 17 | 5 | adantr |  | 
						
							| 18 | 3 4 2 | rngocl |  | 
						
							| 19 | 13 18 | mpd3an3 |  | 
						
							| 20 | 2 1 | grpolid |  | 
						
							| 21 | 20 | eqcomd |  | 
						
							| 22 | 17 19 21 | syl2anc |  | 
						
							| 23 | 10 16 22 | 3eqtr3d |  | 
						
							| 24 | 2 | grporcan |  | 
						
							| 25 | 17 19 13 19 24 | syl13anc |  | 
						
							| 26 | 23 25 | mpbid |  |