(a) In determining the duration and expiration dates of the time periods provided in §§ 2542 and 2543 of this title, the running of the time periods shall be tolled whenever and for as long as the prisoner is unable to stand trial, as determined by the court having jurisdiction of the matter.
(b) No provision of this agreement, and no remedy made available by this agreement, shall apply to any person who is adjudged to be mentally ill.