Eric wrote: > I’d like to prune my tree of the “least-useful” people in it. I could > prune everyone who’s not directly related to (the descendants of the > ancestors of) my kid (the root person in my tree), but I don’t want to be > quite that exclusive. It’s useful to have (whatever-distance) cousins’ > spouses’ parents, for instance, because they provide triangulation > information on that “branch” which is useful when tree-comparing-trying to > figure out whether the Robert Wheeler in my tree is the same as the one in a > DNA cousin’s tree. Sounds like a job for LifeLines (an open source database on SourceForge). The LifeLines programming language has functions ancestorset(), descendantset(), and parentset(), as well as union(). These functions return respectively the set of all ancestors of anyone in the argument set, the set of all descendants of anyone in the argument set, and the set of all parents of anyone in the argument set, (and union does the obvious). You could start with a set containing any collection of interesting persons, such as your kid, and then successively take the union of it and its ancestorset and then the union of that with its descendantset and finally the union of that with its parentset. The resulting set can be output to GEDCOM and then imported into a new database. (There are also spouseset(), childset(), and siblingset() functions if you need them.) John Chandler