In Bell v. Wolfish (441 US 520, 537 [1979]), the Court pointed out that "not every disability ... amounts to 'punishment' in the constitutional sense," distinguishing as between a disability which is "imposed for the purpose of punishment" and that which is "but an incident of some other legitimate governmental purpose" ( id., at 538; see also, Flemming v. Nestor, 363 US 603 [1960]). The Supreme Court, while noting that "the distinction between substance and procedure might sometimes prove elusive" (Miller v. Florida, supra, at 433), also has stated that for an ex post facto violation to occur, the change in law must affect " 'substantial personal rights,' " rather than simply " 'modes of procedure which do not affect matters of substance' " (id., at 430, quoting Dobbert v. Florida, supra, at 293). Hence, "no ex post facto violation occurs if the change in the law is merely procedural and does 'not increase the punishment' " (Miller v. Florida, supra, at 433, quoting Hopt v. Utah, 110 US 574, 590 [1884]).