# This script constructs the language of English
# numerals from "one" to "ninety-nine".
# This is a comment.

# From "one" through "nine":

define OneToNine [{one} | {two}  | {three} | {four} |
                  {five} | {six} | {seven} | {eight} |
                  {nine}];

# It is convenient to define a set of prefixes that
# can be followed either by "teen" or by "ty".

define TeenTyStem [{thir}  | {fif}  | {six}   |
                   {seven} | {eigh} | {nine}];

# From "ten" to "nineteen"
define Teens [{ten} | {eleven} | {twelve} |
              [TeenTyStem | {four}] {teen}];

# Let's define stems that can be followed "ty".
define TyStem [TeenTyStem | {twen} | {for}];

# TenStem is followed either by "ty" or by ty-"
# and a number from OneToNine.

define Tens [TyStem [{ty} | {ty-} OneToNine]];

define OneToNinetyNine [ OneToNine | Teens | Tens ];

push OneToNinetyNine