Find
Z←L⍷R
Find looks for patterns R in L.
It returns a simple boolean array with the same shape as L.
L and R are arbitrary arrays.
But to be useful,
the rank of R
should not be more than the rank of L,
and both arguments should have the same type
(either both character or both numeric).
If R is a scalar,
then Z←L⍷R ←→ L∊R.
If R is not a scalar,
then it represents a contiguous pattern,
which may or may not be found in one or more places in L.
If the arguments are numeric,
then the result is sensitive to ⎕CT.
Examples:
L←3 8⍴'thirteenfourteenfifteen '
L
thirteen
fourteen
fifteen
L⍷'t'
1 0 0 0 1 0 0 0
0 0 0 0 1 0 0 0
0 0 0 1 0 0 0 0
L⍷'teen'
0 0 0 0 1 0 0 0
0 0 0 0 1 0 0 0
0 0 0 1 0 0 0 0
