Planned⊆
Group r←x⊆y
This primitive or feature is planned, that is, it doesn't appear in the most recent released implementation of TinyAPL. Details may change before it is added!
x
is a vector of naturals, with length equal to the tally of y
. r
is a nested vector containing major cells of y
, in the positions marked by corresponding entries in x
. Cells that correspond to a 0
are dropped from r
.