For what it's worth, J's problem with 13 :'y+y' is probably something like:
original y+y made tacit +~ simplified + In other words, since + is commutative, the ~ is "unnecessary". Except, of course, that's only relevant for expressions like 13 :'x+y' So, anyways, I expect that the problem is that the rule that supports simplification for commutative expressions has lost the context that would be necessary to know that it's applicable. If I am right, the simple solution would be to remove that simplification when the arguments are not available (which might be always). -- Raul ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
