Tendence k jednotě v matematice
The genesis of mathematical structures, as exemplified in the work of Charles Ehresmann
The problems of definition
The aim of this paper is to present the great kinds of definitions known in mathematical logic, their goals and their means, from their historical and philosophical background (notably thanks to the proof of two theorems), and in order to situate, within this field, the others contributions which make up this number.
Towards applying computational complexity to foundations of physics.