Adaptation of the closest tree method for a two state quartet to Jukes-Cantor tripod trees

We aim to fit 4-state sequences of DNA characters from three species a tripod tree, whose evolutionary model is Jukes-Cantor. For this purpose, we adapt the closest tree method used in 2-state coming four quartet, where states are purines and pyrimidines CFN. The adaptation requires multi stage methodology called ‘reduction process’. take frequencies character patterns on quartet as parameters search for solutions fit.