(self, p)
list : list RT freq
list : list RT freq
list : list RT freq
def p_list_rt(self, p):
        'list : list RT freq'
        p[0] = p[1][p[1] >= p[3]]
def p_list_rt ( self , p ) : p [ 0 ] = p [ 1 ] [ p [ 1 ] >= p [ 3 ] ]