| Step | Hyp | Ref | Expression | 
						
							| 1 |  | issubgr.v |  | 
						
							| 2 |  | issubgr.a |  | 
						
							| 3 |  | issubgr.i |  | 
						
							| 4 |  | issubgr.b |  | 
						
							| 5 |  | issubgr.e |  | 
						
							| 6 |  | fveq2 |  | 
						
							| 7 | 6 | adantr |  | 
						
							| 8 |  | fveq2 |  | 
						
							| 9 | 8 | adantl |  | 
						
							| 10 | 7 9 | sseq12d |  | 
						
							| 11 |  | fveq2 |  | 
						
							| 12 | 11 | adantr |  | 
						
							| 13 |  | fveq2 |  | 
						
							| 14 | 13 | adantl |  | 
						
							| 15 | 11 | dmeqd |  | 
						
							| 16 | 15 | adantr |  | 
						
							| 17 | 14 16 | reseq12d |  | 
						
							| 18 | 12 17 | eqeq12d |  | 
						
							| 19 |  | fveq2 |  | 
						
							| 20 | 6 | pweqd |  | 
						
							| 21 | 19 20 | sseq12d |  | 
						
							| 22 | 21 | adantr |  | 
						
							| 23 | 10 18 22 | 3anbi123d |  | 
						
							| 24 |  | df-subgr |  | 
						
							| 25 | 23 24 | brabga |  | 
						
							| 26 | 25 | ancoms |  | 
						
							| 27 | 1 2 | sseq12i |  | 
						
							| 28 | 3 | dmeqi |  | 
						
							| 29 | 4 28 | reseq12i |  | 
						
							| 30 | 3 29 | eqeq12i |  | 
						
							| 31 | 1 | pweqi |  | 
						
							| 32 | 5 31 | sseq12i |  | 
						
							| 33 | 27 30 32 | 3anbi123i |  | 
						
							| 34 | 26 33 | bitr4di |  |