def p_ctx_coords(self, p):
        """ ctx_coords : multiplicative_path
                        | ctx_coords COLON multiplicative_path"""
        if len(p) == 2:
            p[0] = [p[1]]
        else:
            p[0] = p[1] + [p[3]]
ctx_coords : multiplicative_path
                        | ctx_coords COLON multiplicative_path