Diagrams and their transformations

In the talk, I understand a diagram as a topological space obtained by gluing a finite number of pairwise non-intersecting rectangles along their sides to a standard circle, equipped with the following two structures. First, a point is chosen and fixed on the circle outside the glued rectangles. Second, the standard orientation is fixed on the circle. (It is assumed that after gluing the rectangles to the circle, the images of different rectangles do not intersect each other and that the images of the complements to the sides of the rectangles do not intersect with the circle.) The main goal of the talk is to introduce the equivalence relation needed for tangle theory on the set of diagrams and to study its simplest properties. This equivalence relation is, as far as the author knows, new, that is, it has not been met or studied in the scientific literature.

Zoom (new link!): https://zoom.us/j/97302991744
Access code: the Euler characteristic of the wedge of two circles
(the password is not the specified phrase but the number that it determines)