issue in python (google colab)

[emiksapitri]

Dear @giorgioroffo,

i use your library as in https://pypi.org/project/PyIFS/#description
but i had an error like this:

---

NameError Traceback (most recent call last)
in <cell line: 6>()
4
5 inf = PyIFS.InfFS()
----> 6 [RANKED, WEIGHT] = inf.infFS(X_train_EN, y_train_column_vector, alpha=0.5, supervision=1, verbose=1)

/usr/local/lib/python3.10/dist-packages/PyIFS/InfFS.py in infFS(self, x_train, y_train, alpha, supervision, verbose)
113 STDMatrix = self.SubtractMin(STDMatrix)
114 sigma_ij = self.DivideByMax(STDMatrix)
--> 115 for i in range( 0,sigma_ij.shape[0] ):
116 for j in range( 0,sigma_ij.shape[1] ):
117 if( math.isnan(sigma_ij[i,j]) or sigma_ij[i,j] < -1 or sigma_ij[i,j] > 1 ):

NameError: name 'math' is not defined

i try to add "import math" before installing pyIFS but it not solve.
do you have any advice to solve this?