\\#1304
issquarefree(0)
\\#1412
core(4*10^15+27)

{
forfactored(d=-100,100,
  if (issquarefree(d[1]) != issquarefree(d[2]), error(d));
  if (isfundamental(d[1]) != isfundamental(d[2]), error(d))
);
}
