| Step | Hyp | Ref | Expression | 
						
							| 1 |  | subgrprop3.v |  | 
						
							| 2 |  | subgrprop3.a |  | 
						
							| 3 |  | subgrprop3.e |  | 
						
							| 4 |  | subgrprop3.b |  | 
						
							| 5 |  | eqid |  | 
						
							| 6 |  | eqid |  | 
						
							| 7 | 1 2 5 6 3 | subgrprop2 |  | 
						
							| 8 |  | 3simpa |  | 
						
							| 9 | 7 8 | syl |  | 
						
							| 10 |  | simprl |  | 
						
							| 11 |  | rnss |  | 
						
							| 12 | 11 | ad2antll |  | 
						
							| 13 |  | subgrv |  | 
						
							| 14 |  | edgval |  | 
						
							| 15 | 14 | a1i |  | 
						
							| 16 | 3 15 | eqtrid |  | 
						
							| 17 |  | edgval |  | 
						
							| 18 | 17 | a1i |  | 
						
							| 19 | 4 18 | eqtrid |  | 
						
							| 20 | 16 19 | sseq12d |  | 
						
							| 21 | 13 20 | syl |  | 
						
							| 22 | 21 | adantr |  | 
						
							| 23 | 12 22 | mpbird |  | 
						
							| 24 | 10 23 | jca |  | 
						
							| 25 | 9 24 | mpdan |  |