fn factorial n : int -> result/EAX : int [
  result/EAX <- copy 1
  {
    compare n, 1
    break-if <=
    var tmp/EBX : int
    tmp/EBX <- copy n
    tmp/EBX <- subtract 1
    var tmp2/EAX : int
    tmp2/EAX <- call factorial, tmp/EBX
    result/EAX <- multiply tmp2/EAX, n
  }
  return result/EAX
]

data structures:

add entry for "factorial" into the Types table, with value (fn int -> int)
add entry for "factorial" into the address table, with value next available address
add entry for "factorial" into the size table, with value size of "0b 0a bb ..."
increase next available address by size of "factorial"