This title has recently been awarded to Petro Kalenyuk, Director of the Institute of Applied Mathematics and Fundamental Sciences, at the University Academic Board meeting, before his 70^{th} birthday. If Mathematics is called ‘the queen of sciences’, then Professor Petro Kalenyuk is a person in attendance to this queen…

It is difficult to characterize a person using one word. It is easier to use three words. That’s what I asked to do ten people, who know Petro Ivanovych intimately. Three epithets were most frequent – decent, intelligent and wise. They spoke about his high level of education. He is an alumnus of Lomonosov Moscow State University. In those days, this prestigious higher educational institution gathered the cream of the crop from the whole Soviet Union. However, education does not always go along with intelligence and decency. You can graduate from several Oxfords or Cambridges and be very far from real intelligence and decency.

I have also conducted a survey among the employees of the Dean’s office and the Department of Mathematics, which was headed by Petro Kalenyuk earlier and now he is professor of this department. I have observed that Petro Ivanovych always speaks calmly and in a low voice. Does he ever raise his voice at his subordinates if they deserve it? Everyone said the same thing, «Never». When I told Petro Ivanovych about this, he smiled and made a comment, «Some lecturers sometimes raise their voice at their students, colleagues or subordinates, explaining that they are too emotional. I recommend, if you are so emotional, then speak in such way with me, Vice-Rectors or Rector…»

We hear a lot about the abyss between the level of knowledge in schools in rural and urban areas. It has always been there. However, there are numerous exceptions. Petro Kalenyuk, ScD, studied at school in a rural area. At that time, it was a school with eleven years of studying in the village Shmyrky of Volochynsk district in Khmelnytsk region. He left school with a gold medal.

– **Petro Ivanovych** **, despite the fact that your parents worked on a collective farm, You inherited a set of genes for successful studying of exact sciences. What was your school Math teacher’s role I forming You as an outstanding prospective mathematician? **

– I will tell you about my last Math teacher in high school Lyubov Hnativna Kramar. She made every effort to make me fond of Mathematics fo life. She told me about a professional journal for Math teachers «Mathematics at School». I saw the contents of Math entrance exams in Moscow State University for the first time in this journal. In the 9^{th} or 10^{th} form, we had a separate subject, Trigonometry. I read and learnt that course book in 10 days. To keep me interested, my teacher gave me a lot of problems to solve, sometimes she asked me to teach a class myself. In the 11^{th} form, I was so cheeky that I thought there was no problem which I wouldn’t be able to solve. At that time, I read a thick book written by academician Y.B. Zeldovych «Calculus for Beginners».

– **Was it your dream to enter Moscow University? **

– No. I just found out in «Komsomolskaya Pravda» newspaper that entrance exams in this university begin at the beginning of July, and not at the beginning of August like in other higher educational institutions. I thought I would have time to try to enter some other place, if I failed in Moscow.

– **Could you remember some outstanding mathematicians that taught at the university at that time? **

– There were a lot of outstanding figures there – Kolmohorov, Alyeksandrov, Yefimov, Hnyedenko, Manin, Arnold… I will mention only former Kyiv citizen Heorhiy Yevhenovych Shylov, a talented scientist and teacher. In fact, he was made to leave Kyiv University because of those who envied him. Such cases were numerous. Heorhiy Yevhenovych taught a course of Mathematical Analysis, which also included Functional Analysis. All his brilliant lectures were published as separate books. There were three volumes of Mathematics, one volume of Linear Algebra. When I was asked to explain something in these subjects, I referred to Shylov’s books. My course projects and diploma project supervisor was Anatoliy Hordiyovych Kostyuchenko, Shylov’s student and Kyiv University alumnus. He was also my first academic mentor.

– **You, obviously, stayed at a dormitory. Who was Your roommate? **

– There was one graduate of an MSU school of Physics and Mathematics, one person from Kirghizia and one person from Mongolia. By the way, all republics of the Soviet Union had their quotas for entering this university. Students from these republics took their entrance exams a home. My friends from Kirghizia and Mongolia did not meet high educational standards. Moreover, both of them had health problems. As a result, they did not graduate from the university.

– **Was there any tension among students because of national differences? **

– I never saw this. We lived as friends, helped each other. There were students from Ukraine. They had their own community, communicated in Ukrainian. There were neither ‘hohols’ nor ‘katsaps’…

– **Were jobs assigned to the graduates after completing their studies? **

– Those who were recommended to become PhD students were not assigned to do certain jobs, if we speak about this particular Moscow university. ‘Recruiter’ used to come to the dormitories where fifth-year students lived in the evenings. They offered various jobs. But they also asked students if they were recommended to become PhD students. If a graduate had such recommendation, they said ‘good bye’ to him/her.

– **Were You recommended to pursue a PhD degree? **

– Yes, I was. I was assigned to Professor Kostyuchenko. Moreover, they did not agree to give me my documents, so that I would not be able to pursue my PhD degree in another city. Several days in a row I was told with a warm smile, «Petya, come tomorrow (in this university students were often addressed by their first names)». I was not able to continue my studies in Moscow because, being a fifth-year student, I married a girl from Lviv. In Lviv, after the determined time to enter postgraduate school, I was blessed on my further was to science by academician Yaroslav Pidstryhach, who later founded and headed Institute for applied problems in Mechanics and Mathematics of the Academy of Sciences of USSR (now it is named after him!).

I started me postgraduate studies in the postgraduate school of Physics and Mechanics Institute of the Academy of Sciences of USSR. My academic mentor was Vitaliy Yakovych Skorobahatko, an outstanding mathematician. He was deeply committed to the science of Mathematics. He initiated holding academic seminars in the House of Scientists twice a week. According to Vitaliy Yakovych, you could cancel the seminar only in case of emergency. For instance, if, God forbid, a war broke out and the House of Scientists was bombed. I worked in various academic institutions. In 1993, I became Head of the Department of Computing Mathematics and Programming. From April 2008 till August 2015, I was Head of the Department of Calculus.

– **It is not a secret that school leavers, who come to higher educational institutions have very poor knowledge of Math, although they take independent testing in Math with the exception of students from colleges. This is not only a problem of our school. Former us president Clinton initiated federal program for improving the level of teaching Math at schools…**

– Furthermore, this problem was relevant for Americans at the time when Soviet Union launched into artificial satellite of the Earth on October 4, 1957, having outdone the USA. America’s federal institutions explained this by lagging behind Soviet Union in the level of mathematical education and science, mathematical modeling in particular. I still have a translation of the article from a prestigious journal of American Mathematical Society of 1966 on this issue.

– **Not many people know that You used to be… a tutor, and future Vice-Rector, Associate Professor Roman Korzh was among Your students. He was considering entering a different educational institution, but You managed to make him so interested in Math, that Roman Orestovych’s mother was surprised by this interest. **

He was not my only student. Vitaliy Yakovych Skorobahatko once said to his colleagues, « Find several students for Petro. He is a young PhD student, he has a family to feed…» I was a very responsible tutor. When I was still studying in Moscow, some students earned extra money tutoring. I did not want to waste time on this. I thought I’d better read some new book in my major to know more than others.

– **I remember that several years ago, there was a discussion in our university who should teach a course in Calculus for students of different specialities – builders, radio mechanics, power engineering specialists, mechanics. There were suggestions that such course should be taught by people who know Mathematics and the characteristic features of the given speciality well. **

– Mathematics is an integral science. There is no separate Math for builders or radio mechanics. Another thing is that heads of the departments should advise us what to stress more. Once Omelyan Bobyk was First Vice-Rector in Franko University. Then he was Head of the Department of Mathematics and Computer Technologies in Lviv Banking Institute. He told me that some people complained to him that a different Mathematics was taught there. He asked his colleagues to write what and how they should teach. A long time passed and no one wrote anything. Finally Omelyan Ivanovych was told, «Leave us alone, you teach well and we are happy about that!»

–** I was pleased to find out that Your close friend Professor Orest Lozynskiy, who, together with a group of co-authors, published a textbook very necessary for students, thanked You in the Foreword for Your academic consulting. **

– I am always ready to help any academics who need consulting or advice in Mathematics.

– **It seems that all laws and theorems in Mathematics have already been discovered. I looked up the website of Your Department and saw how many topics academics are working on. Where is the main niche of Your Department, what is the most important in the fundamental and applied works? **

– It is, first of all, analytical and numerical methods of researching physical and mechanical fields, processes, co-operative and structural phenomena in solid bodies and liquids. It is also research of boundary value problems in Mathematical Physics, theories of functions and functional analysis. We also study problems and theoretical models in linear and differential algebras. We have a rather strong algebraic school. Scientific studies in mathematical analysis are developing successfully. 10 professors and 35 associate professors are working creatively at the Department of Mathematics now.

– **A personal question: is Your wife a mathematician as well? **

– No, she is a power engineering expert, she worked as a power engineering economist.

**– PhD or ScD?**

– She worked as an engineer. We decided that it was enough to have one scientist in the family. But our eldest granddaughter (I have four of them) graduated from Trinity College in Dublin is pursuing her Master’s degree in Cambridge University. She is studying Computer Biology, which gives her an opportunity to combine her school dream about medicine with Math.

**– Most of our lecturers claim that their best rest is in their garden… **

– I have a little plot of land with a primitive hut. But my wife is renting my garden…