↑ Take r←x↑y
x must be a scalar or vector of integers. r is the result of taking from each axis of y as many elements as specified by the corresponding element of x. If x is positive, the first x elements are taken; if x is negative, the last x elements are taken; if x is zero, no element is taken.
Outfix
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!
If (an element of) x is nested, it must be a two-element vector, with the first item a nonnegative integer and the second item a nonpositive integer. In that case, the items taken on the corresponding axis are the first ⊃x and the last -⊇x, except that if they overlap they're taken only once.