To appreciate a great person, one must be at a certain distance from him. Of course, over time all of the estimates and the emphasis in the work of Anatolii Volodymyrovych will be put in the rank by the future generations of mathematicians. But now we can certainly say that the Theory of Probability with Skorokhod’s contribution into it is a fundamentally different thing as compared to what it was before.

It should be noted that even prominent mathematicians of our days are impressed  by  Skorokhod’s achievements, not only by the volume of his contribution, but also by his exquisite designs in the construction of new theories  and elegant swing thoughts in grounding of certain assertions. I repeatedly have heard enthusiastic reviews of visiting mathematicians of the impossibility that all Skorokhod’s works could belong to one person. In general, Anatolii Volodymyrovych avoided talking about how he managed to do it, but he told to some of his close Moscow friends that he had taught himself from the young years to the daily intense reflection on the problem. For him the day during which he did not learn something new was lost in vain. I think that there have been not many such days of the kind in the life of Anatolii Volodymirovych. Owing to his intense work day after day, the creative spark given to him from God is now a bright shining star of the first magnitude on the mathematical frontier.

Talking about the method of Anatolii Volodymyrovych, then I remembered his words that one should go directly to the problem, without any tricks. Hence - direct probabilistic methods about which there are now so many conversations. Of course, it is not so easy to explain what it means ─  "to go directly to the problem". Perhaps, from  the place where   Anatolii Volodymyrovych  stood he could go straightly  to the problem. But if you stood in some other place, perhaps, there was the "direct approach to the problem” too. These things are subtle, they affect the very essence of the incomprehensible creative process. In this regard, I remember the following episode:

It was about 30 years ago. Once, I turned on the TV and saw on the screen Volodymyr Vyshensky who summarized the results of math competition held before. Among others, he analyzed the proof of such assertion: a finite number of parabolic shapes (parabolic shape is a part of the plane bounded by the branches of a parabola) cannot cover the entire plane. The author’s proof impressed me by its beauty. It was based on the fact that a straight line on the plane which is not parallel to the axis of symmetry of the parabola, has in common with the corresponding parabolic shape not more than a finite interval. Therefore, if there is a finite number of parabolic shapes on a plane, then each line on it which is not parallel to the axis of symmetry of any of those parabolas will have in the intersection of those figures at most a finite number of bounded intervals.  But a straight line cannot be covered by a finite number of bounded  intervals. Once after I met Anatolii Volodymtrovych and told him that I was impressed by the beauty of the solution of a problem, which I learned from Volodymyr Vyshensky. "And what a problem?"  ─  he asked. I formulated the problem. He thought a few seconds and said the following: "Every parabola can be enclosed into an arbitrarily small corner. Therefore, if there is a finite number of parabolas, they can be enclosed into corners such that their total value is strictly less than the full angle. But the whole plane cannot be covered by such angles”. Then he asked about the solution, which I learned from Vyshensky. I told him, ending with the words: "You must recognize that it is a beautiful solution”. He said while in deep thought: "Yes, beautiful ". But in his words I did not feel any enthusiasm.

In fact, his concept of a beauty in mathematics was special. In his lectures, he had never said any  monologue about the beauty of a consideration or a formula. I think that the very train of thoughts in the proof of a fact seemed to him so that it was beautiful itself and needed no further decoration. His lectures were capacious. In my teaching practice I not once tried to fit in one of my lecture the material of Skorokhod’s one lecture, but all such attempts appeared futile. Anatolii Volodymyrovych had a principle, which he always kept to in his scientific work, namely, he never used the assertions of other mathematicians which he was unable to prove or did not see how  to do it. In other words, he never constructed his proofs on the facts that seemed to be unclear for him. I knew only one exception to this rule in his work. I mean some inequalities proved  by the Moscow mathematician Nicolai Krylov (who is now a professor at the University of Minneapolis, USA)  that now are well-known to the experts on the theory of stochastic differential equations as Krylov’s estimates. I think that Skorokhod spent a lot of efforts to find a "direct" proof of those estimates, and so he believed in their correctness. Therefore, he also used them. But I once was a witness of his discussion with Krylov, during which Anatoly Volodymyrovych expressed his displeasure at how his friend argued to prove his estimates. Of course, the estimates’ author had his own view on that proof, and this conversation was very interesting. Now let me say a few words about Anatolii Volodymyrovych’es attitude to his students. I think in that respect he is close to the Grigorii Skovoroda: no authority to  a student, no mentoring tone in discussion. Only personal interest to the problem which both of them were trying to solve, joint search for the ways to solve it. In concluding my speech, I want to mention about another passion of Anatolii Volodymyrovych. I mean his passion to poetry. During our walks, it was in Lansing in the States or here, in Kiev, he could during hours read by heart poems by Osip Mandelstam, Anna Akhmatova, Boris Pasternak, Lina Kostenko, Joseph Brodsky et al.

I am deeply grateful to the Fate for being in my life such a Teacher and a Friend.

M.I. Portenko