diff --git a/Nasal/geo.nas b/Nasal/geo.nas
index 7408b1e0f..552307d76 100644
--- a/Nasal/geo.nas
+++ b/Nasal/geo.nas
@@ -344,32 +344,14 @@ var PositionedSearch = {
 		if (a == nil or b == nil) return 0;
 		return (a == b or a.id == b.id);
 	},
-	condense: func(vec) {
-		var ret = [];
-		foreach (var e; vec)
-			if (e != nil) append(ret, e);
-		return ret;
-	},
-	diff: func(old, new) {
-		var removed = old~[]; #copyvec
-		var added = new~[];
-		# Mark common elements from removed and added:
-		forindex (OUTER; var i; removed)
-			forindex (var j; new)
-				if (me._equals(removed[i], added[j])) {
-					removed[i] = added[j] = nil;
-					continue OUTER;
-				}
-		# And remove those common elements, returning the result:
-		return [new, me.condense(removed), me.condense(added)];
-	},
 	update: func(searchCmd=nil) {
 		if (searchCmd == nil) searchCmd = me.searchCmd;
-		(me.result, var removed, var added) = me.diff(me.result, call(searchCmd, nil, me.obj));
-		foreach (var e; removed)
-			call(me.onRemoved, [e], me.obj);
-		foreach (var e; added)
-			call(me.onAdded, [e], me.obj);
+		var old = me.result~[]; #copyvec
+		me.result = call(searchCmd, nil, me.obj);
+		positioned.diff( old,
+										 me.result,
+										 func call(me.onAdded, arg, me.obj),
+										 func call(me.onRemoved, arg, me.obj) );
 	},
 	# this is the worst case scenario: switching from 640 to 320 (or vice versa)
 	test: func(from=640, to=320) {
@@ -384,4 +366,3 @@ var PositionedSearch = {
 	  }); # ~ takes 
 	}, # of test
 };
-