Validating Act can operate retrospectively to cure anomaly in statute but can’t impose penalty retro

ST : Legislature can enact validating legislation with retrospective effect to cure a deficiency pointed out in a Court judgment in a provision which had as its object the restriction of sales tax incentives to an amount calculated on a proportional basis. Such legislation is not unconstitutional. However, if such validating legislation provides for imposition of penalty with retrospective effect, it would be unconstitutional to that extent only