throwstd::runtime_error(MESSAGE("Incompatible dimensions #"<<dim.first<<"["<<m1.dimension(dim.first)<<"] and #"<<dim.second<<"["<<m1.dimension(dim.second)<<"]"));
throwstd::runtime_error(SPELL_STRING("Incompatible dimensions #"<<dim.first<<"["<<m1.dimension(dim.first)<<"] and #"<<dim.second<<"["<<m1.dimension(dim.second)<<"]"));