def _REOM(y,t,pot,l2):
    """
    NAME:
       _REOM
    PURPOSE:
       implements the EOM, i.e., the right-hand side of the differential 
       equation
    INPUT:
       y - current phase-space position
       t - current time
       pot - (list of) Potential instance(s)
       l2 - angular momentum squared
    OUTPUT:
       dy/dt
    HISTORY:
       2010-07-20 - Written - Bovy (NYU)
    """
    return [y[1],
            l2/y[0]**3.+_evaluateplanarRforces(pot,y[0],t=t)]
def _REOM ( y , t , pot , l2 ) : return [ y [ 1 ] , l2 / y [ 0 ] ** 3. + _evaluateplanarRforces ( pot , y [ 0 ] , t = t ) ]
NAME:
       _REOM
    PURPOSE:
       implements the EOM, i.e., the right-hand side of the differential 
       equation
    INPUT:
       y - current phase-space position
       t - current time
       pot - (list of) Potential instance(s)
       l2 - angular momentum squared
    OUTPUT:
       dy/dt
    HISTORY:
       2010-07-20 - Written - Bovy (NYU)