RE: Sense gate metal1 in pcell(lowest hierarchy) and draw metal1 path to connect all gates in a row of 10 pcells in current hierarchy(1 hierarchy above than the lowest hierarchy).

Not surprising that it doesn't work, because it would be attempting to add two lists. You have two lists of lists that need to be added - for that you'd have to do: b=mapcar(lambda((p1 p2) mapcar('plus p1 p2)) a '((0.038 0.038) (0.038 0.038))) Or simpler (since it's the same offset): b=foreach(mapcar p1 a foreach(mapcar n1 p1 n1+0.038)) This form will work for a list of any number of points, and is probably a bit more transparent. BTW, I did think about deleting Tom's Japanese post for being a non-English post, but I supposed (from sticking it through Google Translate) that it was an attempt at humour... Regards, Andrew.