and his petitions for writs of habeas corpus and mandamus. 6 . We do not read our recent opinion in Rather v. Suthers, 973 P.2d 1264, 1267 (Colo.1999), to suggest otherwise. In Rather, we stated that we could not grant the petitioner habeas corpus relief because at that time he was only eligible for discretionary parole and was not yet entitled to immediate release in the form of mandatory parole. However, in Rather, unlike here, we were reviewing the denial of a habeas corpus petition on its merits, and Rather was not merely seeki 49, 20 L.Ed.2d 426 (1968) (rejecting prematurity doctrine and allowing a prisoner to bring a habeas corpus challenge to the second of two consecutive sentences while still serving the first); Chatman-Bey v. Thornburgh, 864 F.2d 804, 808-09 (D.C.Cir.1988) (<HOLDING>). However, tírese cases interpret the federal
holding that federal habeas corpus relief does not lie for errors of state law holding that a writ of habeas corpus is a state prisoners sole federal remedy for challenging the duration of his imprisonment in order to obtain a speedier release in the future holding that federal prisoners challenging determination of their future parole eligibility date must bring their suit under habeas corpus theory holding that the claims of two state prisoners challenging the validity of state procedures for determining parole eligibility were properly brought under  1983 and did not have to be brought in a habeas proceeding holding that habeas petition challenging the state boards decision to defer his scheduled parole release date was rendered moot by prisoners release from custody on parole and subsequent incarceration for violating his parole