Contains vs is in

[hh]

Please forget my last two posts, they contain wrong statements.
Haven't seen that this is already implemented using the term "subsequence of elements":

From the dictionary.
Target contains Needle if and only if the elements of Needle occur as a _subsequence of the elements_ of Target.

So I should use the dictionary and can test by myself.
I thought erroneously of analogies to (counted) sets, sorry.