Given a monomial ideal I, returns all square-free monomials in a minimal generating set of I.
i1 : R = QQ[x,y,z];
i2 : I = ideal(x*y,y*z,x^2); o2 : Ideal of R
i3 : squarefreeGens(I) o3 = {y*z, x*y} o3 : List