What is the function of と in とある?


What is the function of `と` in
[とある](http://dic.yahoo.co.jp/dsearch?p=%E3%81%A8%E3%81%82%E3%82%8B&stype=0&dtype=0&dname=0ss)?

It doesn't seem to be the particle `と`\--it doesn't seem to attach to whatever
comes before it, which particles generally do. It also doesn't seem to fit any
of the uses of the particle `と` described my in books. So, I guess it must be
something other than a particle.

So far, I've found [this answer on
知恵袋](http://detail.chiebukuro.yahoo.co.jp/qa/question_detail/q1180590256). It
suggests that `と` is [this 副詞 meaning 「そのように」
](http://dic.yahoo.co.jp/dsearch?enc=UTF-8&p=%E3%81%A8&dtype=0&dname=0ss&stype=1&index=113712700000&pagenum=11),
the same `と` in `とにかく`. And, as @Chocolate points out in a comment,
[学研全訳古語辞典](http://kobun.weblio.jp/content/%E3%81%A8%E3%81%82%E3%82%8B) agrees
that the `と` in `とある` is a 副詞.

However, [in another
comment](https://japanese.stackexchange.com/questions/9847/what-is-the-
function-of-%E3%81%A8-in-%E3%81%A8%E3%81%82%E3%82%8B#comment20873_9847),
Chocolate points out that 広辞苑 says `と` _is_ a particle. I'm not sure how to
reconcile this with the other information I've found so far. (I don't have 広辞苑
myself, so I can't verify the quote.) As I said before, it doesn't seem to
behave like a particle to me, because it doesn't attach to what comes before
it. Is 広辞苑 wrong?

What is this `と` exactly?




In "とある宝飾店" (a jewelry store), とある is one word, and not と + ある. As a single
word it means "a" or "some". It signifies that the speaker doesn't want to
specify which jewelry stor eit is.

Note that there is also a sentence where とある is two words と (particle) + ある
(verb: exist), such as "メニューには売り切れとある" (menu says [it is] sold out.)

