@Uriel
X⊃Y
(as indicated by its symbol and pairing with
⊃Y
)
picks and discloses a single particular element at each level of of depth.
X⌷Y
(a ligature of
[
and
]
)
indexes at the outermost depth, and can thus be used to select major cells of any array, and like bracket indexing, it doesn't disclose the selection.