| Step | Hyp | Ref | Expression | 
						
							| 1 |  | iscgrg.p |  | 
						
							| 2 |  | iscgrg.m |  | 
						
							| 3 |  | iscgrg.e |  | 
						
							| 4 |  | elex |  | 
						
							| 5 |  | fveq2 |  | 
						
							| 6 | 5 1 | eqtr4di |  | 
						
							| 7 | 6 | oveq1d |  | 
						
							| 8 | 7 | eleq2d |  | 
						
							| 9 | 7 | eleq2d |  | 
						
							| 10 | 8 9 | anbi12d |  | 
						
							| 11 |  | fveq2 |  | 
						
							| 12 | 11 2 | eqtr4di |  | 
						
							| 13 | 12 | oveqd |  | 
						
							| 14 | 12 | oveqd |  | 
						
							| 15 | 13 14 | eqeq12d |  | 
						
							| 16 | 15 | 2ralbidv |  | 
						
							| 17 | 16 | anbi2d |  | 
						
							| 18 | 10 17 | anbi12d |  | 
						
							| 19 | 18 | opabbidv |  | 
						
							| 20 |  | df-cgrg |  | 
						
							| 21 |  | df-xp |  | 
						
							| 22 |  | ovex |  | 
						
							| 23 | 22 22 | xpex |  | 
						
							| 24 | 21 23 | eqeltrri |  | 
						
							| 25 |  | simpl |  | 
						
							| 26 | 25 | ssopab2i |  | 
						
							| 27 | 24 26 | ssexi |  | 
						
							| 28 | 19 20 27 | fvmpt |  | 
						
							| 29 | 4 28 | syl |  | 
						
							| 30 | 3 29 | eqtrid |  | 
						
							| 31 | 30 | breqd |  | 
						
							| 32 |  | dmeq |  | 
						
							| 33 | 32 | eqeq1d |  | 
						
							| 34 | 32 | adantr |  | 
						
							| 35 |  | simpll |  | 
						
							| 36 | 35 | fveq1d |  | 
						
							| 37 | 35 | fveq1d |  | 
						
							| 38 | 36 37 | oveq12d |  | 
						
							| 39 | 38 | eqeq1d |  | 
						
							| 40 | 34 39 | raleqbidva |  | 
						
							| 41 | 32 40 | raleqbidva |  | 
						
							| 42 | 33 41 | anbi12d |  | 
						
							| 43 |  | dmeq |  | 
						
							| 44 | 43 | eqeq2d |  | 
						
							| 45 |  | fveq1 |  | 
						
							| 46 |  | fveq1 |  | 
						
							| 47 | 45 46 | oveq12d |  | 
						
							| 48 | 47 | eqeq2d |  | 
						
							| 49 | 48 | 2ralbidv |  | 
						
							| 50 | 44 49 | anbi12d |  | 
						
							| 51 | 42 50 | sylan9bb |  | 
						
							| 52 |  | eqid |  | 
						
							| 53 | 51 52 | brab2a |  | 
						
							| 54 | 31 53 | bitrdi |  |