# ‘A Tribute to John Horton Conway’ – Glossary of terms

Nim: a two-person mathematical game; see https://en.wikipedia.org/wiki/Nim

[2] Dedekind cuts: a method of constructing the real numbers from the rational numbers; see https://en.wikipedia.org/wiki/Dedekind_cut

[3] von Neumann ordinals: a way of defining and extending the notion of natural number; see https://en.wikipedia.org/wiki/Ordinal_number#Von_Neumann_definition_of_o...

[4] Surreal numbers: an extension of the notion of number, created by John Conway; see https://www.cut-the-knot.org/WhatIs/Infinity/SurrealNumbers.shtml

[5] Sprague-Grundy theory of impartial games: a way of studying two-person combinatorial games with perfect information; see https://en.wikipedia.org/wiki/Sprague%E2%80%93Grundy_theorem

[6] John Conway’s Game of Life: a zero-player game invented by John Conway, in which the entire future evolution of a game is decided by the initial state; see https://en.wikipedia.org/wiki/Conway%27s_Game_of_Life

[7] Sphere packing: a study of the problem of packing spheres of identical size into a finite region, in an optimal manner; see https://en.wikipedia.org/wiki/Sphere_packing

[8] Knot theory: a study of mathematical knots; see https://en.wikipedia.org/wiki/Knot_theory

[9] Leech lattice: see https://en.wikipedia.org/wiki/Leech_lattice

[10] Conway Group: see https://en.wikipedia.org/wiki/Conway_group

[11] Monstrous Moonshine: see https://en.wikipedia.org/wiki/Monstrous_moonshine