  ***   at top-level: factorback(Vecsmall([1,2]),[3,4])
  ***                 ^---------------------------------
  *** factorback: incorrect type in factorback [not a vector] (t_VECSMALL).
  ***   at top-level: factorback('x,[3,4])
  ***                 ^--------------------
  *** factorback: incorrect type in factorback [not a vector] (t_POL).
  ***   at top-level: factorback([1,2,3],[3,4])
  ***                 ^-------------------------
  *** factorback: incorrect type in factorback [not an exponent vector] (t_VEC).
  ***   at top-level: factorback([1,2],'x)
  ***                 ^--------------------
  *** factorback: incorrect type in factorback [not an exponent vector] (t_POL).
Total time spent: 0
