"in possession of a ruler, a protractor, a compass, a slide-rule"

That would indicate a different terrorist group, Geo-Metry. They are desperately hard to catch because the get around so much and tend to shoot off at obtuse angles when pursued. They are known to frequent pi shops and have been accused of attempting to "trap a zoid". Try not to move in their circles. If you see one, call for help immediately. Never confront one as attempting to square off with one is a job for experts. (Ex-perts are old perts which have gone a bit soggy...) Members of Geo-Metry are known to commit sin alone or cosin with another of their ilk. Some are reported to have a good tan. Some are two dimensional, which is usually plane to see.


Regards,
Ed, who thinks a slide rule is a piece of playground equipment.