A compact <real tree> is a compact <metric space> $(T,d)$ such that any $x,y\in T$ are joined by a unique arc, and that arc is <isometric> to $[0,d(x,y)]$. The <multiplicity of a point in a real tree> $a\in T$ is the number of <connected components> of $T\setminus\{a\}$.

Solution

Past exam of the mathematics course of the University of Cambridge / 2021 / iii / Paper 220 / 1 / a / Solution

 Solution (source code)