A couple easy ones on the data.int-map contrib library, when maintainers are feeling up for it: https://clojure.atlassian.net/jira/software/c/projects/DIMAP/issues/DIMAP-8 - Union, intersection and difference have only 2 arguments versions https://clojure.atlassian.net/jira/software/c/projects/DIMAP/issues/DIMAP-24 - PersistentIntSet doesn't override java.lang.Object#toString
Thanks Alex!
lot of test failures with the DIMAP-8 patch dropped a comment about impl in DIMAP-24