Correct notation to illustrate the product of a weighted path

23 Views Asked by At

I am struggling to represent a situation using the correct mathematical notation. I have a graph that consists of a series of nodes (1-4) and edges which represent movement pathways between nodes. The edges have an attribute d, which represents the distance between the two adjacent nodes.

an example of a network

The probability of successfully moving between two adjacent nodes i and j is a function of distance (d):

$$P_{success} = e^{-d_{i,j}/10}$$

e.g. for each adjacent pair of nodes in the figure above the probability of success would be:

$$P_{success, 1,2} = e^{-0.5/10} = 0.95$$

$$P_{success, 2,3} = e^{-0.1/10} = 0.9$$

$$P_{success, 3,4} = e^{-1.5/10} = 0.86$$

Now I apply an additional toll to the probability of success ($P_{toll}$) which can range from 0 to 1. If $P_{toll}$ = 0.5 then the probability of moving from node 1 to node 4 would be:

$$(0.95 * 0.5) * (0.9 * 0.5) * (0.86 * 0.5) = 0.09$$

My Question:

How do I present a general form of the above situation mathematically?

This is my attempt (which I know is wrong), hopefully I am at least on the right track…

$$\prod^j_{i:j}(e^{-d_{i,j}/10} P_{toll})$$

Edit

To clarify, I am not only interested in the distance from node 1 to 4, but from any node to any other node.