| Step | Hyp | Ref | Expression | 
						
							| 1 |  | istrkg.p |  | 
						
							| 2 |  | istrkg.d |  | 
						
							| 3 |  | istrkg.i |  | 
						
							| 4 |  | simpl |  | 
						
							| 5 |  | simpr |  | 
						
							| 6 | 5 | oveqd |  | 
						
							| 7 | 6 | eleq2d |  | 
						
							| 8 | 5 | oveqd |  | 
						
							| 9 | 8 | eleq2d |  | 
						
							| 10 | 7 9 | 3anbi12d |  | 
						
							| 11 | 5 | oveqd |  | 
						
							| 12 | 11 | eleq2d |  | 
						
							| 13 | 5 | oveqd |  | 
						
							| 14 | 13 | eleq2d |  | 
						
							| 15 | 5 | oveqd |  | 
						
							| 16 | 15 | eleq2d |  | 
						
							| 17 | 12 14 16 | 3anbi123d |  | 
						
							| 18 | 4 17 | rexeqbidv |  | 
						
							| 19 | 4 18 | rexeqbidv |  | 
						
							| 20 | 10 19 | imbi12d |  | 
						
							| 21 | 4 20 | raleqbidv |  | 
						
							| 22 | 4 21 | raleqbidv |  | 
						
							| 23 | 4 22 | raleqbidv |  | 
						
							| 24 | 4 23 | raleqbidv |  | 
						
							| 25 | 4 24 | raleqbidv |  | 
						
							| 26 | 1 3 25 | sbcie2s |  | 
						
							| 27 |  | df-trkge |  | 
						
							| 28 | 26 27 | elab4g |  |