New law not retroactively revoking previously acquired teacher's health-related reduced working hours right.

The Supreme Court reversed a lower court decision that had denied a teacher's right to continued reduced working hours based on a 1995 medical assessment. The teacher argued that the 1996 amendment to the Teachers' Card did not explicitly revoke her previously granted reduction, which was validly issued by the school director under existing laws. The court held that new legislation cannot retroactively deprive a subject of a right successfully acquired under prior regulations unless a clear derogating statutory provision exists.