How to apply probabilistic method to call variants in a simple example.

Question

[ManuelDB]

I am trying to understand how the Bayes' theorem is applied on probabilistic methods to infer a variant called from NGS alignment reads. I understand the basics of the Bayes' theorem but not as much I would like because when I tried to applied in a simple example I can't. I mean, I am not able to see how to calculate the probability that the variant called in the following example is T applying the Bayes' theorem

—-----------------T—----------------
—-----------------T—----------------
—-----------------T—----------------
—-----------------C—----------------
—-----------------T—----------------     7 Aligned Reads
—-----------------C—----------------
—-----------------C—----------------
—-----------------T—----------------   Reference