Mathematical library with basic data structures and operations in PHCv2. The mathematical library contains general tools that are not specific for polynomial homotopy continuation. New in this release are the multi-precision numbers and the use of Ada 95. Math_Lib : 1. general mathematical library |-- Numbers : 1.1. number representations |-- Matrices : 1.2. matrices and linear-system solvers |-- Polynomials : 1.3. multivariate polynomial systems |-- Supports : 1.4. support sets and linear programming The directory Numbers specifies the coefficient rings and contains definitions of floating-point and complex numbers. The coefficient rings are implemented by means of packages that can be used for instantiating generic packages. In Matrices we find a generic package vectors, matrices of integer, floating-point and complex numbers. Solvers of linear systems are provided. The directory Polynomials contains the packages to deal with multivariate polynomials and systems. To deal with support sets and polytopes, linear-programming methods have been implemented in the directory Supports.