| Step | Hyp | Ref | Expression | 
						
							| 1 |  | isubgrvtx.v |  | 
						
							| 2 | 1 | isubgrvtx |  | 
						
							| 3 |  | simpr |  | 
						
							| 4 | 2 3 | eqsstrd |  | 
						
							| 5 |  | eqid |  | 
						
							| 6 | 1 5 | isubgriedg |  | 
						
							| 7 |  | resss |  | 
						
							| 8 | 6 7 | eqsstrdi |  | 
						
							| 9 |  | simpl |  | 
						
							| 10 | 5 | uhgrfun |  | 
						
							| 11 | 10 | adantr |  | 
						
							| 12 | 1 | isubgruhgr |  | 
						
							| 13 |  | eqid |  | 
						
							| 14 |  | eqid |  | 
						
							| 15 | 13 1 14 5 | uhgrissubgr |  | 
						
							| 16 | 9 11 12 15 | syl3anc |  | 
						
							| 17 | 4 8 16 | mpbir2and |  |