Both expressions give the correct answer. The right argument of membership determines the target of the items to be sought, just like the left argument of index-of determines the targets. In my opinion, the APL\360 team made a mistake by making x∊y the same as x∊,y. We are struggling with the consequences of this in Dyalog APL, where ⍳ was recently extended to accept higher-ranked left arguments. The mistake from long-ago prevents the similar extension to ∊.
On Thu, Nov 20, 2014 at 10:19 AM, Devon McCormick <[email protected]> wrote: > Hi - > > I was just burned by this apparent anomaly: > 1 e. 0~: i. 2 2 > 0 > > but > 1 e. , 0~: i. 2 2 > 1 > > Has anyone else noticed this? Am I right in thinking this is incorrect > behavior in the first case? > > Regards, > > Devon > -- > Devon McCormick, CFA > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
