From: M.J.T. Guy [mailto:mjtg@cus.cam.ac.uk] > > Good point. I was proposing to look for both "PL_na" and "na" etc. > If a PL... symbol was found, we can assume the module has been updated > so no POLLUTE is needed. I'd only force POLLUTE if there were > polluting symbols present and *no* PL... ones. But... In the case of na, a good fix for (silly example) { na = 12; } is { STRLEN na; na = 12; } instead of { PL_na = 12; } because access to a local variable is faster than access to a global. So a fixed module may still refer to na rather than PL_na. (I assume you don't propose to scan for declarations...?) I'm not sure of the value of the heuristic approach in any case, but I thought I'd add this datapoint... Paul.