Describe the current plan for data structures for numbers
Clear number property lists at start of parser
Add a search-and-replace sweep to the first step for the number parser

This will make subsequent work a lot easier.
Use correct argument in search/replace step
Add an initial (empty) test file for the number part of the code
At present, probably best to hard-code the tl here

The normalisation routine will only be used with one tl and as it is
internal there is little gain in passing the name around.
Parse comparators

The assumption is added here that we are dealing with real number to
begin with. That's necessary as the intermediate results have to go
somewhere.