Letter Glad for the addressee'a understanding of the reasons for Ershov's failure to come to Denmark; discussing the addressee's plans to visit Novosibirsk and the material he sent to Ershov; hope for the meeting and discussion at the IFIP Congress Date: 16.06.1980 Original document language: English Authors: Andrei Petrovich Ershov Addressee: Dines Bjorner