find function
lfind(P, L) returns the longest suffix of L that begins with an
element satisfying P.
lExample:
lfind(odd, [2, 4, 6, 7, 9, 10, 12])
==> [7, 9, 10, 12]
==> [7, 9, 10, 12]
lAs with map, etc., find is often used with anonymous
functions.