The Ada sources of PHC are organized in the following tree of directories:

 Ada                       : sources of PHC
  |-- System               : 0. UNIX dependencies, e.g.: timing package
  |-- 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
  |-- Homotopy             : 2. homotopy and solution lists
  |-- Continuation         : 3. path-tracking routines
  |-- Root_Counts          : 4. root counts and homotopy construction
  |      |-- Product       : 4.1. linear-product start systems
  |      |-- Implift       : 4.2. implicit lifting
  |      |-- Stalift       : 4.3. static lifting
  |      |-- Dynlift       : 4.4. dynamic lifting
  |      |-- Symmetry      : 4.5. exploitation of symmetry relations
  |-- Main                 : 5. main dispatcher
  |-- Objects              : 6. to install, type: make all
