derivation_relativistic_addition_4_velocity

def main():

    import sympy

    b1 = sympy.Symbol('b1')
    b2 = sympy.Symbol('b2')
    b12 = (b1+b2)/(1+b1*b2)

    w1 = sympy.Symbol('w1',positive=True)
    w2 = sympy.Symbol('w2',positive=True)
    w12 = b12/sympy.sqrt(1-b12**2)

    w12 = w12.subs(b1,w1/sympy.sqrt(1+w1**2)).subs(b2,w2/sympy.sqrt(1+w2**2))
    w12 = w12.simplify()

    sympy.pprint(w12)

if __name__ == '__main__':

    main()