**Leo Moser** (11 April 1921, Vienna – 9 February 1970, Edmonton) was an Austrian-Canadian mathematician, best known for his polygon notation.

A native of Vienna, Leo Moser immigrated with his parents to Canada at the age of three. He received his Bachelor of Science degree from the University of Manitoba in 1943, and a Master of Science from the University of Toronto in 1945. After two years of teaching he went to the University of North Carolina to complete a Ph.D., supervised by Alfred Brauer.^{ [1] } There, in 1950, he began suffering recurrent heart problems. He took a position at Texas Technical College for one year, and joined the faculty of the University of Alberta in 1951, where he remained until his death at the age of 48.

In 1966, Moser posed the question "What is the region of smallest area which will accommodate every planar arc of length one?".^{ [2] } Rephrased to consider the planar arc a "worm", this became known as Moser's worm problem and is still an open problem in discrete geometry.

**Combinatorics** is an area of mathematics primarily concerned with counting, both as a means and an end in obtaining results, and certain properties of finite structures. It is closely related to many other areas of mathematics and has many applications ranging from logic to statistical physics, from evolutionary biology to computer science, etc.

**Harold Scott MacDonald** "**Donald**" **Coxeter**, was a British and later also Canadian geometer. He is regarded as one of the greatest geometers of the 20th century.

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In graph theory, a branch of mathematics, the **Moser spindle** is an undirected graph, named after mathematicians Leo Moser and his brother William, with seven vertices and eleven edges. It is a unit distance graph requiring four colors in any graph coloring, and its existence can be used to prove that the chromatic number of the plane is at least four.

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**George Barry Purdy** was a mathematician and computer scientist who specialized in cryptography, combinatorial geometry and number theory. Purdy received his Ph.D. from the University of Illinois at Urbana–Champaign in 1972, officially under the supervision of Paul T. Bateman, but his de facto adviser was Paul Erdős. He was on the faculty in the mathematics department at Texas A&M University for 11 years, and was appointed the Geier Professor of computer science at the University of Cincinnati in 1986.

**Károly Bezdek** is a Hungarian-Canadian mathematician. He is a professor as well as a Canada Research Chair of mathematics and the director of the Centre for Computational and Discrete Geometry at the University of Calgary in Calgary, Alberta, Canada. Also he is a professor of mathematics at the University of Pannonia in Veszprém, Hungary. His main research interests are in geometry in particular, in combinatorial, computational, convex, and discrete geometry. He has authored 3 books and more than 130 research papers. He is a founding Editor-in-Chief of the e-journal Contributions to Discrete Mathematics (CDM).

**Moser's worm problem** is an unsolved problem in geometry formulated by the Austrian-Canadian mathematician Leo Moser in 1966. The problem asks for the region of smallest area that can accommodate every plane curve of length 1. Here "accommodate" means that the curve may be rotated and translated to fit inside the region. In some variations of the problem, the region is restricted to be convex.

**Peter Manfred Gruber** was an Austrian mathematician working in geometric number theory as well as in convex and discrete geometry.

In mathematics, a **topological graph** is a representation of a graph in the plane, where the *vertices* of the graph are represented by distinct points and the *edges* by Jordan arcs joining the corresponding pairs of points. The points representing the vertices of a graph and the arcs representing its edges are called the *vertices* and the *edges* of the topological graph. It is usually assumed that any two edges of a topological graph cross a finite number of times, no edge passes through a vertex different from its endpoints, and no two edges touch each other (without crossing). A topological graph is also called a *drawing* of a graph.

**Haim Hanani** was a Polish-born Israeli mathematician, known for his contributions to combinatorial design theory, in particular for the theory of pairwise balanced designs and for the proof of an existence theorem for Steiner quadruple systems. He is also known for the Hanani–Tutte theorem on odd crossings in non-planar graphs.

**Peter McMullen** is a British mathematician, a professor emeritus of mathematics at University College London.

In mathematics, **Harborth's conjecture** states that every planar graph has a planar drawing in which every edge is a straight segment of integer length. This conjecture is named after Heiko Harborth, and would strengthen Fá**integral Fáry embedding**. Despite much subsequent research, Harborth's conjecture remains unsolved.

- ↑ Leo Moser at the Mathematics Genealogy Project
- ↑ W. Moser, G. Bloind, V. Klee, C. Rousseau, J. Goodman, B. Monson, J. Wetzel, L. M. Kelly7, G. Purdy, and J Wilker, Fifth edition,
*Problems in Discrete Geometry*, McGill University, Montreal, 1980

- O'Connor, John J.; Robertson, Edmund F., "Leo Moser",
*MacTutor History of Mathematics archive*, University of St Andrews . - Posthumous biographical appreciation, dated May 19, 1970, by mathematician Max Wyman, president of the University of Alberta from 1969 to 1974
- Comprehensive list of 88 papers, lectures and other works authored by Leo Moser
- April 1961 photograph of Leo Moser

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