algstr1 2 1 http://www.openmath.org/cdfiles/cdgroups/algstr1.cdg Basic Algebraic Structures This is the first version of the CC CD group. O.Caprotti 1999-20-08 relation0: Binary relations properties, equivalence relation, orders relation0 http://www.openmath.org/cd/relation0.ocd semigroup: semigroup as setoid with a binary operation semigroup http://www.openmath.org/cd/semigroup.ocd setoid:: setoid as a set with an equivalence relations defined on its elements setoid http://www.openmath.org/cd/setoid.ocd Inductive definition of natural numbers indnat http://www.openmath.org/cd/indnat.ocd