Add readme.md

readme.md

+# MATH1222
+
+This is a repo for the project of the course 
+*MATH122: Introduction aux processus stochastiques*.
+
+## Statement
+
+The statement can be found [here](projet-math1222-2025.pdf). This project was done in groups of two.
+The objective of the project was to model the mutations of ADN.
+
+### Complementary informations
+
+One of the usages of phylogenetic trees is to find relations between beings.
+
+The first thing we need to model is the evolution of the ADN. 
+We have a mutation when one of the nucleotide of the sequence changes over time.
+We take in that the mutation is not influenced by the nucleotides and that it's without memory.
+
+We can thus represent this with a Markov chain. We use the substitution model of Kimura.
+We won't manipulate the markov chain of the whole sequence because there would be too many possibilities.
+The chain is also reversible meaning the probability of doing one inversion is the same as doing the opposite.
+
+Because we don't have the sequence of the nodes and the racine but only the leafs we need to use
+
+$$P(s_1,\cdots,s_5\|T)=\sum_{s'_1, s'_2,\cdots} P(s_1, \cdots,s_5,s'_1,s'_2,\cdots,s'_{N-1}|T)$$
+
+<span style="color:#FF0000">DEADLINE:</span> **09/05/2025**
+