Edit: I believe I misunderstood the question, so my answer may be misleading. But I'll leave it here anyway. Read @mrcslws's answer below.
The term "unordered sets" is confusing. From your description, I believe you are actually talking about temporal sequences that are seemingly randomly repeated throughout a stream of data. For example, the letters
eat, which could be in
Depending on the data is encoded, you might even call this a spatial pattern, not a temporal one, especially if you are encoding at the word (not letter) level.
Anyway, yes, HTM can recognize temporal sequences, but it is harder to identify when they are occurring. @marion has been working on a project focused on this, but I'm not sure what the status is.