Appellant filed a habeas petition in the district court seeking immediate reinstatement of his mandatory release from a five-year federal sentence. He alleged that he had never been informed whether his mandatory release had been revoked although nearly five months had elapsed since his revocation hearing before the parole board. 1

Appellant’s full sentence expired on June 1, 1971, on which date he was released from federal custody. Thus the appeal is rendered moot and is therefore dismissed.