あり+と: What does と do when preceded by a verb stem?

Question

In the following sentence:

彼女はそれを手に入れるためにありとあらゆる方法を試みた。
She tried every possible means to get it.

と is preceded by あり, which I take to be the verb stem of ある. I do not see what this ありと adds to the sentence.

Usually, when I see a と that I cannot immediately identify, my first attempt is to think of it as either a *conditional marker, or a *particle that connects two clauses to describe a sequential past event. One of them usually applies.
*Layman's attempts at describing grammar

However, in both of the abovementioned cases, と has to follow the dictionary form of verbs, not the stem. Therefore, this is something different.

Could someone please help me identify what this grammar point is? よろしくお願いいたします！

Answer 1

「ありとあらゆる」 means the same as 「ありとある」 -- "every single ~~", "every possible ~~", etc.

So, what is this 「と」? As usual, monolingual dictionaries are our best friends. 大辞林 says under definition 🈩 - ⑩ for case particles:

⑩ 「…と…」の形{かたち}で、同一{どういつ}の動詞{どうし}を重{かさ}ね意味{いみ}を強{つよ}める。現代語{げんだいご}では限{かぎ}られた言{い}い方{かた}としてしか用{もち}いられない。 「あり－あらゆる人{ひと}」 「生{い}き－し生{い}ける物」

meaning:

⑩ It links the same verb to emphasize its meaning in the form of 「…と…」. In modern Japanese, it is only used in limited (idiomatic) expressions. 「あり－あらゆる人」 「生き－し生ける物」

Thus, it might be faster to remember 「ありとあらゆる」 as a fixed expression rather than analysing it grammatically as this 「と」 is not even used outside of these idiomatic expressions.

The other example 「生きとし生けるもの」, by the way, means "all animate things". A cool phrase to know if you ask me.