Here is what I came with. The 0 _1 is top-left point of the "merged" rectangle, and 8 5 is bottom-right point.
3 _1 (<./"1@(,.&0)@[ , 2&{.@] >. [ + _2&{.@]) 3 4 5 6 0 _1 8 5 Note that if instead of , you use -~ 3 _1 (<./"1@(,.&0)@[ -~ 2&{.@] >. [ + _2&{.@]) 3 4 5 6 8 6 you'll get the size of the rectangle. ----- In trying to work more on this problem I have come up with the following intermediate problem for which I would like some help... ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm