event log

> 0   (sequence "a" (some 1) "c")
> 1   "a"
  1 > "a"
> 2   (some 1)
> 3   1
  3 > 1
> 4   1
  4 > 1
> 5   1
  5 > 1
  2 > (some 1)
> 6   "c"
  6 > "c"
  0 > (sequence "a" (some 1) "c")