Hi Gerd, please find attached a small patch for preventing a crash when two regular expressions are used but the 'and' or 'or' separating them is missing, for example: landuse=meadow & (name~'[Mm]eadow' name~'[Ff]ield') {delete name;} The existing code crashes with the following trace: java.lang.AssertionError at uk.me.parabola.mkgmap.osmstyle.eval.RegexOp.setSecond(RegexOp.java:49) at uk.me.parabola.mkgmap.osmstyle.eval.ExpressionReader.runOp(ExpressionReader. java:180) at uk.me.parabola.mkgmap.osmstyle.eval.ExpressionReader.saveOp(ExpressionReader .java:143) at uk.me.parabola.mkgmap.osmstyle.eval.ExpressionReader.readConditions(Expressi onReader.java:62) at uk.me.parabola.mkgmap.osmstyle.RuleFileReader.loadFile(RuleFileReader.java:1 15) at uk.me.parabola.mkgmap.osmstyle.RuleFileReader.load(RuleFileReader.java:86) at uk.me.parabola.mkgmap.osmstyle.StyleImpl.readRules(StyleImpl.java:302) at uk.me.parabola.mkgmap.osmstyle.StyleImpl.<init>(StyleImpl.java:160) at uk.me.parabola.mkgmap.osmstyle.StyleImpl.readStyle(StyleImpl.java:554) at uk.me.parabola.mkgmap.reader.osm.OsmMapDataSource.createConverter(OsmMapData Source.java:289) at uk.me.parabola.mkgmap.reader.osm.OsmMapDataSource.setupHandler(OsmMapDataSou rce.java:187) at uk.me.parabola.mkgmap.reader.osm.o5m.O5mBinMapDataSource.load(O5mBinMapDataS ource.java:43) at uk.me.parabola.mkgmap.reader.osm.OsmMapDataSource.load(OsmMapDataSource.java :138) at uk.me.parabola.mkgmap.main.MapMaker.loadFromFile(MapMaker.java:154) at uk.me.parabola.mkgmap.main.MapMaker.makeMap(MapMaker.java:52) at uk.me.parabola.mkgmap.main.Main$1.call(Main.java:265) at uk.me.parabola.mkgmap.main.Main$1.call(Main.java:261) at java.util.concurrent.FutureTask.run(Unknown Source) at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) at java.lang.Thread.run(Unknown Source) With the patch, I get an error message as follows: Error in style: Error: (points:76): Invalid arguments to REGEX: FUNCTION ($[Mm]eadow) and REGEX (($name~'[Ff]ield')) (Actually I get the message 4 times, but that is a minor issue.) I have moved 3 lines of code from before various syntax checks to after the checks. Please try the patch and commit if happy. Thanks, Mike