Package: pari
Version: 2.6.2 (development 16006-f55c8ae)

There is no garbage collection inside products, but it is easy
to reach the stack limit.

gp> vector(500,k,'x^k)*vectorv(500,k,'y^k)
  ***   at top-level: vector(500,k,'x^k)*vectorv(500,k,'y^k)
  ***                                   ^--------------------
  *** _*_: the PARI stack overflows !
  current stack size: 8000000 (7.629 Mbytes)
  [hint] you can increase GP stack with allocatemem()

  ***   Break loop: type 'break' to go back to GP prompt
break>