Converts a number to English and vice versa.
Tested with SWI-Prolog (SWI-Prolog version 5.10.4 for amd64).
- Extend to numbers above 999, below zero, and decimal notation.
- Make the conversion back and forth more elegant (meta-interpreter?)
- Test on a corpus.
- Extend to other variations (e.g. Roman numerals, other languages/dialects/usages, fuzzy)
- Read description of A005589.