(self, i)
Every lie algebra has a unique root system.
        Given a root system Q, there is a subset of the
        roots such that an element of Q is called a
        simple root if it cannot be written as the sum
        of two elements in Q.  If we let D denote the
        set of simple roots, then it is clear that every
        element of Q can be written as a linear combination
        of elements of D with all coefficients non-negative.

        This method returns the ith simple root of G_2
        Example
        =======
        >>> from sympy.liealgebras.cartan_type import CartanType
        >>> c = CartanType("G2")
        >>> c.simple_root(1)
        [0, 1, -1]
Every lie algebra has a unique root system.
        Given a root system Q, there is a subset of the
        roots such that an element of Q is called a
        simple root if it cannot be written as the sum
        of two elements in Q.  If we let D denote the
        set of simple roots, then it is clear that every
        element of Q can be written as a linear combination
        of elements of D with all coefficients non-negative.
Every lie algebra has a unique root system . Given a root system Q there is a subset of the roots such that an element of Q is called a simple root if it cannot be written as the sum of two elements in Q . If we let D denote the set of simple roots then it is clear that every element of Q can be written as a linear combination of elements of D with all coefficients non - negative .
def simple_root(self, i):
        """
        Every lie algebra has a unique root system.
        Given a root system Q, there is a subset of the
        roots such that an element of Q is called a
        simple root if it cannot be written as the sum
        of two elements in Q.  If we let D denote the
        set of simple roots, then it is clear that every
        element of Q can be written as a linear combination
        of elements of D with all coefficients non-negative.

        This method returns the ith simple root of G_2
        Example
        =======
        >>> from sympy.liealgebras.cartan_type import CartanType
        >>> c = CartanType("G2")
        >>> c.simple_root(1)
        [0, 1, -1]

        """
        if i == 1:
            return [0, 1, -1]
        else:
            return [1, -2, 1]
def simple_root ( self , i ) : if i == 1 : return [ 0 , 1 , - 1 ] else : return [ 1 , - 2 , 1 ]