Recursive Descent, Tail Recursion, & the Dreaded Double Divide

(a)

18  /  6  /  3
--  -  -------
 |  |  |
 |  |  remainder of string passed to Term function 
 |  operator '/'  (first pending operation)
 factor

18  /  6  /  3
--  -  -  -  -
 |  |  |  |  |
 |  |  |  |  remainder of string passed to Term function again
 |  |  |  operator '/' (second pending operation)
 |  |  factor
 |  operator '/' (first pending operation)
 factor

18  /  6  /  3
--  -  -  -  -
 |  |  |  |  |
 |  |  |  |  factor
 |  |  |  operator '/' (second pending operation)
 |  |  factor
 |  operator '/' (first pending operation)
 factor

18  /  2
--  -  -
 |  |  |  
 |  |  term
 |  operator '/' (first pending operation)
 factor

Figure 1: The parsing process.