move lemma less_multiset_doubletons
Created originally on Bitbucket by abentkamp (Alexander Bentkamp)
Was already merged in Bitbucket before import, marked as merged by the import user
There will be about 1h of downtime on 2020-03-02 at 13:00 UTC+1 (change of servers and upgrade to Heptapod 0.20.0 final)
Created originally on Bitbucket by abentkamp (Alexander Bentkamp)
Was already merged in Bitbucket before import, marked as merged by the import user