// lingyuan-xinfa.c 靈元心法// written by deaner// Modified by Venus Oct.1997inherit FORCE;int valid_enable(string usage) { return usage == "force"; }int valid_learn(object me)// need more limit here{    return 1;}int practice_skill(object me){    return notify_fail("靈元心法只能用學習的來增加熟練度。\n");}string exert_function_file(string func){    return SKILL_D("lingyuan-xinfa/") + func;}