The probability coordinates for a phylogenetic tree model have one coordinate for each possible outcome of the model. A possible outcome is any labeling of the leaves of the tree by elements of the group $G$ of the model. Thus the number of coordinates is $|G|^n$ where $n$ is the number of leaves.
A variable name for the ring can be passed using the optional argument Variable. Otherwise the symbol p is used.
i1 : pRing(4,CFNmodel)
o1 = QQ[p ..p ]
0,0,0,0 1,1,1,1
o1 : PolynomialRing
|
i2 : pRing(3,JCmodel)
o2 = QQ[p ..p ]
0,0,0 3,3,3
o2 : PolynomialRing
|
The object pRing is a method function with options.