a=:2 (a &+)\ 1 2 3 3 0 0 3 4 0 3 4 5
*(a & =:)\ 1 2 3* |syntax error | (a&=:)\1 2 3 *Why error?* Even more simple example a + & ^. 5 2.30259 a =: & ^. 5 |syntax error | a=: &^.5 *Why compose don't support assigment?* Sergey P.S. a =: @ ^. 5 |syntax error | a=: @^.5 ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
