+;; This is the ccl-decode-thai-xtis automaton.
+;;
+;; "WRITE x y" == (insert (make-char 'thai-xtis x y))
+;; "write x" == (insert x)
+;; rx' == (tis620-to-thai-xtis-second-byte-bitpattern rx)
+;; r3 == "no vower nor tone"
+;; r4 == (charset-id 'thai-xtis)
+;;
+;; | input (= r0)
+;; state |--------------------------------------------
+;; | consonant | vowel | tone
+;; ---------+-------------+-------------+----------------
+;; r1 == 0 | r1 = r0 | WRITE r0,r3 | WRITE r0,r3
+;; r2 == 0 | | |
+;; ---------+-------------+-------------+----------------
+;; r1 == C | WRITE r1,r3 | r2 = r0' | WRITE r1,r3|r0'
+;; r2 == 0 | r1 = r0 | | r1 = 0
+;; ---------+-------------+-------------+----------------
+;; r1 == C | WRITE r1,r2 | WRITE r1,r2 | WRITE r1,r2|r0'
+;; r2 == V | r1 = r0 | WRITE r0,r3 | r1 = r2 = 0
+;; | r2 = 0 | r1 = r2 = 0 |
+;;
+;;
+;; | input (= r0)
+;; state |-----------------------------------------
+;; | symbol | ASCII | EOF
+;; ---------+-------------+-------------+-------------
+;; r1 == 0 | WRITE r0,r3 | write r0 |
+;; r2 == 0 | | |
+;; ---------+-------------+-------------+-------------
+;; r1 == C | WRITE r1,r3 | WRITE r1,r3 | WRITE r1,r3
+;; r2 == 0 | WRITE r0,r3 | write r0 |
+;; | r1 = 0 | r1 = 0 |
+;; ---------+-------------+-------------+-------------
+;; r1 == C | WRITE r1,r2 | WRITE r1,r2 | WRITE r1,r2
+;; r2 == V | WRITE r0,r3 | write r0 |
+;; | r1 = r2 = 0 | r1 = r2 = 0 |