OPINION
HERVEY, J.,delivered the opinion of the Court,
in which KELLER, P.J., MEYERS, WOMACK, KEASLER, HOLCOMB and COCHRAN, J.J., joined.Serving a life sentence on an aggravated robbery conviction, applicant complains in this habeas corpus proceeding that the government refuses to release him to mandatory supervision. We hold that a life-sentenced inmate is not eligible for release to mandatory supervision.
When applicant committed his crime in 1981, the law governing eligibility for release to mandatory supervision provided that an inmate not under a sentence of death “shall be released to mandatory supervision” when the “calendar time he has served plus any accrued good conduct time equal the maximum term to which he was sentenced.” See Article 42.12, Section 15(c), V.A.C.C.P., (West 1981). This law has not substantively changed since then. See Section 508.147(a), Tex. Gov’t Code *328(providing for release of inmate to mandatory supervision “when the actual calendar time the inmate has served plus any accrued good conduct time equals the term to which the inmate was sentenced”). Under a literal reading of this law, it is mathematically impossible to determine a mandatory supervision release date on a life sentence because the calendar time served plus any accrued good conduct time will never add up to life. See Boykin v. State, 818 S.W.2d 782, 785 (Tex.Cr.App.1991) (judiciary must follow statute’s “plain language”).1
Finally, interpreting the mandatory release statute to mandate a life-sentenced inmate’s release to mandatory supervision would also require this Court to perform a legislative function which we decline to do. See Boykin, 818 S.W.2d at 785 (our constitution assigns the lawmaking function to the legislature while assigning the law interpreting function to the judiciary). This Court would arbitrarily have to substitute some number of years for a life sentence to make it possible to calculate a mandatory supervision release date. This is the Legislature’s job. See id.
Habeas corpus relief is denied.
JOHNSON, J., filed a dissenting opinion, in which PRICE, J., joined.. The government has never released life-sentenced inmates to mandatory supervision. During this time the Legislature has amended the mandatory supervision law several times without providing for the release of life-sentenced inmates to mandatory supervision. The Legislature could easily have done this especially since it has expressly provided that some life-sentenced inmates are eligible for discretionary parole. See generally Article 508.145, Tex. Gov’t Code. All of this indicates that the Legislature does not intend for life-sentenced inmates to be eligible for release to mandatory supervision. See Boykin, 818 S.W.2d at 785 (judiciary must give effect to legislative intent of a statute).