- cool decay example, suppose you have lambda, decay rate per second between two nuclides
- (half life is just ln2 / lambda)
- probability that an atom decays in an interval is lambda * dt
- with multiple decays, probability of a decay path is found by just multiplying all probabilities along the chain
- decay chain of highest probability? give each edge a 'length' of -1*log(lambda) and then find shortest path via astar or dijkstra
- because adding log probabilities is the same as multiplying probabilities
- since log is negated, shortest path is most likely decay route

ex 2.1

- simple graphs are undirected with no loops
- regular graphs are those in which vertices have the same number of neighbors (vertices are of the same degree or valency)
- complete graphs: each pair of vertices has an edge connecting them
- paths are sequences of vertices that connect vertices
- cycles are sequences of vertices starting and ending at the same vertex
- forests are graphs with no cycles
- trees are connected graphs with no cycles
- connected graphs are those that contain a path from every node to every other node

ex 2.2, 2.3 and 2.4