"On Evans's vague object from set theoretic viewpoint" （共著）

5月はじめに「哲学的論理学雑誌」に投稿した私とh師の共著論文の件で、4ヶ月待ってやっと返事が来た。内容は、修正と補足を条件にacceptするそうだ。やった！！待った甲斐がありました。
abstractは以下の通り。

Gareth Evans proved that if two objects are indeterminately equal then they are different in reality. He insisted that this contradicts the assumption that there can be vague objects. However we show the consistency between Evans's proof and the existence of vague objects within classical logic.
We formalize Evans's proof in a set theory without the axiom of extensionality, and we define a set to be vague if it violates extensionality with respect to some other set. There exist models of set theory where the axiom of extensionality does not hold, so this shows that there can be vague objects.

pdfファイルを大学のサイトにおいてあります。興味のある方はどうぞご覧ください。

reviewerによれば、

The paper contributes in an interesting way to the investigation of the vagueness phenomenon

ただし修正要求箇所がたくさんあったので、また忙しくなりそう。