A SyStem for rigorouS or formal development of Software uSing the notion of {AbStract Machine}S to Specify and deSign Software SyStemS. The B-Method iSSupported by the B-Toolkit. AbStract MachineS are Specified uSing the AbStract Machine Notation (AMN) which iS in turn baSed on the mathematical theory of GeneraliSed SubStitutionS. (1995-03-13)