On 09.02.2013 10:07, David Bower wrote: > gmp-5.1.0 and compile with "g++ -lgmpxx -lgmp ../arbitraryPrecisionArithmetic_1.cpp" I don't know, whether this solves your problem, but usually, linker options should be last, i.e.: g++ ../arbitraryPrecisionArithmetic_1.cpp -lgmpxx -lgmp cheers, Steffen