from the BIT journal.

Request for assistance in organization of Prof. Froberg's short trip to Irkutsk for a tour to lake Baikal.

Under the general agreement about an exchange of researchers between Swedish Universities and SO AN in Novosibirsk, the authors invite A.Ershov to visit Sweden during the early fall of 1971.

to the proofs of the paper from BIT editor

The editor of BIT thanks prof. Ershov for his valuable assistance in completing the 20th annual volume of the journal.

Swedish side confirms that addressee's visit to Sweden will be arranged according to the agreement between Soviet and Swedish Academies.

The author thanks for the research reports and suggests to discuss a date of addressee's visit. Something like October 1 would be suitable for them.

The author thanks for the letter and referee reports. He has learned about the addressee's illness and told about his own similar operation in June 1977. He is ready to answer any guestions. He asks, if possible, to find some of senior scientists who would be interested to work at Lund University.

The author suggests to the addressee to spend the first week after the IFIP conference in Lund and the next week in Stockholm.

to the review of the paper "On context free and Szilard language".

inviting to contribute to a special issue of the "BIT" magazine which will be dedicated to the 60th birthday of Peter Naur.

discussion of a possible visit of A.P. Ershov to Sweden in the 4th quarter of 1971