PLaSM: functional language for computing with geometry. The design language PLaSM is a geometry-oriented extension of a subset of FL. FL Language: FL (programming at Function Level) is a language developed by the Functional Programming Group of IBM Research Division at Almaden (USA) [BWW90, BWWLA89]. The FL language, on the line of the Backus’ Turing lecture [Backus78] introduces an algebra over programs and has an awesome expressive power. PLaSM Language: PLaSM, (the Programming LAnguage for Solid Modeling) is a ”design language” for geometric and solid parametric design, developed by the CAD Group at the Universities ”La Sapienza” and ”Roma Tre” [PS92, PPV95]. The language is strongly inFLuenced by FL. With few sintactical differences, it can be considered a geometric extension of a FL subset.