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