Words which incorporate "and", "or" or "not" confuse the parser.

[soferio]

If you attempt to filter using the word "Notice", it wil be treated as "not" "ice".

The regexes which identify the "and", "or", "not" operators should be modified to terminate with a word boundary regex, being "\b". So my proposal is that lines 38, 46 and 50 in expression.js be modified as follows:

Line 38 would change from:

return this.match(/^NOT/i).toUpperCase();

to:

return this.match(/^NOT\b/i).toUpperCase();

and lines 46 and 50 would be similarly modified.