procedure convergents(seq)
   local prev_p, prev_q, p, q, t

   seq := copy(seq)

   prev_p := [0, 1]
   prev_q := [1, 0]

   while t := get(seq) do {
      p := t * prev_p[2] + prev_p[1]
      q := t * prev_q[2] + prev_q[1]
      suspend rational(p, q, 1)
      prev_p[1] := prev_p[2]
      prev_p[2] := p
      prev_q[1] := prev_q[2]
      prev_q[2] := q
      }

end