It's easier than that. Your solution is: *∨/ (⊂'bar') ⍷ x*
This is because X⍷Y returns a list of the elements of X that matches Y. Then ∨/ is just a reduction of that. Regards, Elias On 9 May 2014 11:56, Blake McBride <blake1...@gmail.com> wrote: > Forgive the question, but my experience is only with the original APL and > not APL2. I have a (general array) vector. Each element is a string > vector. For example: > > x←'abcd' 'efg' 'hijkl' > > Now, if I have: > > y←'hijkl' > > z←'hhh' > > How can I tell if y is in x? How can I tell if z is in x? > > I can easily do this with a loop, but that's not APL. > > This is as far as I've gotten: > > x∘.=y > > (I am one function away from completing a keyed files system for GNU APL!) > > Thanks! > > Blake > >