(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.

        In B_n the first n-1 simple roots are the same as the
        roots in A_(n-1) (a 1 in the ith position, a -1 in
        the (i+1)th position, and zeroes elsewhere).  The n-th
        simple root is the root with a 1 in the nth position
        and zeroes elsewhere.

        This method returns the ith simple root for the B series.

        Example
        ========
        >>> from sympy.liealgebras.cartan_type import CartanType
        >>> c = CartanType("B3")
        >>> c.simple_root(2)
        [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.

        In B_n the first n-1 simple roots are the same as the
        roots in A_(n-1) (a 1 in the ith position, a -1 in
        the (i+1)th position, and zeroes elsewhere).  The n-th
        simple root is the root with a 1 in the nth position
        and zeroes elsewhere.

        This method returns the ith simple root for the B series.

        Example
        ========
        >>> from sympy.liealgebras.cartan_type import CartanType
        >>> c = CartanType("B3")
        >>> c.simple_root(2)
        [0, 1, -1]

        """
        n = self.n
        if i < n:
            return self.basic_root(i-1, i)
        else:
            root = [0]*self.n
            root[n-1] = 1
            return root
def simple_root ( self , i ) : n = self . n if i < n : return self . basic_root ( i - 1 , i ) else : root = [ 0 ] * self . n root [ n - 1 ] = 1 return root