version 5 by Michael Callaghan
Section: Rules for number questions
We test the answer to a number question using the phrase 'the number understood'.
There are two default rules for processing answers to number questions.
The first rule, called 'the invalid number reply rule', operates where the player enters an answer to a number question that is not a number. If the question is a closed number question, the outcome is retry. If the question is an open question, the outcome is parse.
The last rule, called 'the default number question rule', has the outcome exit.