All very good points AnomalousMonk!

>I'm not sure I understand why the poor sentence must be mauled so relentlessly in your final approach, but it's fine with me if it works for you.

I was just experimenting a few more things.

>I note that the approach you use does not seem to take account of longest versus shortest matches: 'tor SET6' can never match because 'tor' precedes it in the ordered alternation. Perhaps this is your intent, but be aware that as the code stands, longest-shortest matching behavior depends on the order in which phrases appear in the phrase list. (This is touched on in paragraph 5 of Re^3: phrase match.) See example below.

Very good point. Yes, my 'phrase list' would be in the decreasing order of phrase string length.

>I also note there is still no provision for a 'sentence' ending in a period, although again, perhaps this contingency will never arise. Example also below.

Yes, I will have the period removed in a preprocessing step.

Thanks a lot again.