Corrigendum: Unrealizability Logic

This is a corrigendum for the article "Unrealizability Logic" by Jinwoo Kim, Loris D’Antoni, and Thomas Reps, published in Proc. ACM Program. Lang. 7, POPL, Article 23 (January 2023), https://doi.org/10.1145/3571216. The authors, with the help of Shaan Nagy, discovered that there was an implicitly made assumption when stating soundness, and a flaw in the completeness proof of the original paper. This corrigendum clarifies the assumption made in the soundness statement and rectifies the completeness proof.