

def simple_root(self, i):
    'The ith simple root of F_4\n\n        Every lie algebra has a unique root system.\n        Given a root system Q, there is a subset of the\n        roots such that an element of Q is called a\n        simple root if it cannot be written as the sum\n        of two elements in Q.  If we let D denote the\n        set of simple roots, then it is clear that every\n        element of Q can be written as a linear combination\n        of elements of D with all coefficients non-negative.\n\n        Examples\n        ========\n\n        >>> from sympy.liealgebras.cartan_type import CartanType\n        >>> c = CartanType("F4")\n        >>> c.simple_root(3)\n        [0, 0, 0, 1]\n\n        '
    if (i < 3):
        return basic_root((i - 1), i)
    if (i == 3):
        root = ([0] * 4)
        root[3] = 1
        return root
    if (self == 4):
        root = ([Rational((- 1), 2)] * 4)
        return root

dataset/ETHPy150Open sympy/sympy/sympy/liealgebras/type_f.py TypeF.simple_root/VarMisuse@68/351 `i`->`self`