Hi Roberto, Here it is the new error: make all-am make[3]: Entering directory `/opt/ppl-1.1pre3/src' /opt/bin/bash ../libtool --tag=CXX --mode=compile g++ -DHAVE_CONFIG_H -I. -I.. -I.. -I../src -I/opt/include -g -O2 -frounding-math -W -Wall -MT PIP_Tree.lo -MD -MP -MF .deps/PIP_Tree.Tpo -c -o PIP_Tree.lo PIP_Tree.cc libtool: compile: g++ -DHAVE_CONFIG_H -I. -I.. -I.. -I../src -I/opt/include -g -O2 -frounding-math -W -Wall -MT PIP_Tree.lo -MD -MP -MF .deps/PIP_Tree.Tpo -c PIP_Tree.cc -fPIC -DPIC -o .libs/PIP_Tree.o Linear_Expression_inlines.hh: In constructor 'Parma_Polyhedra_Library::PIP_Tree_Node::Artificial_Parameter::Artificial_Parameter(const Parma_Polyhedra_Library::Linear_Expression&, const Parma_Polyhedra_Library::GMP_Integer&)': Linear_Expression_inlines.hh:445: error: 'Parma_Polyhedra_Library::Coefficient Parma_Polyhedra_Library::Linear_Expression::gcd(Parma_Polyhedra_Library::dimension_type, Parma_Polyhedra_Library::dimension_type) const' is private PIP_Tree.cc:897: error: within this context Linear_Expression_inlines.hh:452: error: 'void Parma_Polyhedra_Library::Linear_Expression::exact_div_assign(const Parma_Polyhedra_Library::GMP_Integer&, Parma_Polyhedra_Library::dimension_type, Parma_Polyhedra_Library::dimension_type)' is private PIP_Tree.cc:912: error: within this contextmake[3]: *** [PIP_Tree.lo] Error 1 make[3]: Leaving directory `/opt/ppl-1.1pre3/src' make[2]: *** [all] Error 2 make[2]: Leaving directory `/opt/ppl-1.1pre3/src' make[1]: *** [all-recursive] Error 1 make[1]: Leaving directory `/opt/ppl-1.1pre3' make: *** [all] Error 2 Thanks alot,Hugo Gomes