Petr Hájek has been leading a busy and fruitful mathematician's life for nearly half a century. He has explored set theory, expert systems, data analysis, arithmetic, fuzzy logic and some other areas, always leaving a permanent imprint. As a great teacher and supervisor, he opened the door to the world of mathematical logic to many generations of students. He is involved in numerous committees, boards and societies, and the recipient of many honours for his scientific achievements. On Sunday mornings, he is the church organist at St. Clement's, Prague. He is married and has two children.
Petr Hájek will turn seventy on February 6, 2010.