A/N: This is what happens when I go to class, specifically a linguist class. We were looking at compositional semantics and all that came to mind when I heard about tautology was Aoko saying "Thank goodness. Kaito is Kaito." This works as an AU, and may or may not be apart of my The Strange Case of Ran Mouri. I'm pretty much aging the characters up so that they're both freshmen at university, and Kaito has been Kaitou Kid since their last year of high school. Aoko's understanding of these linguistic terms are novicely applicated, just like the writer using them. And why does Aoko have blue magics? Because, why not?

Prompt: #53 (incalculable) from 64_damn prompts

"Truth Values and Conditions of a Sentence"

"Katio is Kaito."

Aoko had written this sentence a dozen of times since that damned Kaitou Kid had made his reappearance. She had it play over and over in her mind since her father first accused her best friend of being the phantom thief. It repeated itself like a broken record since she first saw Kid's familiar face up-close under the harsh moonlight. Every time, there had been a way to prove it wrong. Kaito had been on a date with her during one of Kid's heists. Kid had pulled off a mask to reveal a face of a young woman then a young man.

It even played once she had graduated and started attending university. During on of her lunches, an American friend of Aoko's had went off on a tirade about linguistics that left Aoko baffled. Eventually, the friend better explained the concepts she learned about, and it was nothing for Aoko to try to apply it to this sentence she had often repeated to herself over the last year and a half.

"Kaito is Kaito. "

There was no need to find a way to explain the conditions the world needed to be in for this to be true. Kaito was named Kaito. Kaito would put on dazzling magic tricks, flashing a cocky grin as he outdid himself again and again. Kaito would be a bit oblivious to her attempts at showing him that she now cared for him in a way that was a step to the left of a friend. Kaito was that idiot who always seemed distant, but would put himself on a limb for her-and it always ended in fantastical results.

"Kaito is Kaito." There was no need to explain the reason why the sentence was true in value. It was a tautology, Aoko's friend had explained. Something is something, assuming that something was true.

But the idea of Kaito being Kaitou Kid still tugged at her mind. It was a contradiction. Aoko knew there was no conditions met that made this true, so the truth value of the sentence "Kaito is Kid" was false. It was like saying a dog is a fish.

Oh, she could be sure there was a possible world out there that met these conditions, but this wasn't one. Kid was unscrupulous; Kaito was...not a saint. The conditions simply didn't match up.

At least, that was how she thought until she found herself able to summon up blue magics in the palm of her hands able to "bring out" or "reveal," as Akako explained. The conditions of the possible world of magics had changed for the sentence "magic really exists" to become true in value. Now as she thought about it, Aoko found that maybe the change in the conditions had also changed the value of "Kid is uncatchable" in the same moment.

And, much to her horror, simply seeking the truth beneath Kid's monocle and top hat had been enough to change the conditions for the sentence "Kaito is a Kaitou" as well.