Raul suggested: >I'd be tempted to use > ([: g x h y) f y
This is incorrect. The spec states x and y are nouns. The sentence above would always signal domain error. Correct formulations using cap would be: x (([: g h) f ]) y or: x (] f~ [: g h) y which I do not think can claim an advantage over my earlier: x (g@:h f ]) y -Dan ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
