coefficients - How to locate a list within a list?

for example f[{1,2,3,4},{2,3}]=True, f[{1,2,3,4},{2,3,4}]=True but f[{1,2,3,4},{2,4}]=False. Which function should I use because I don't want to reinvent the wheel. Thanks in advance

Answer

We may use pattern matching:

f[a_, {ss__}] := MatchQ[a, {___, ss, ___}]

Testing:

f[{1, 2, 3, 4}, {2, 3}]          (* True  *)
f[{1, 2, 3, 4}, {2, 3, 4}]       (* True  *)
f[{1, 2, 3, 4}, {2, 4}]          (* False *)

This should work in any version of Mathematica and it is nearly equivalent in performance to SequencePosition: (as measured in version 10.1 under Windows)

f1[Range[10000], {5000, 5001, 5002}] // RepeatedTiming
f[Range[10000], {5000, 5001, 5002}]  // RepeatedTiming

{0.000444, True}

{0.000475, True}