Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
At the start of the Damage Step, if this card battles a Pendulum Monster: This card's ATK and DEF become half its current ATK and DEF until the end of the Damage Step.
--ディノンの鋼鉄騎兵
--Steel Cavalry of Dinon
local s,id=GetID()
function s.initial_effect(c)
	Pendulum.AddProcedure(c)
	--atk/def
	local e1=Effect.CreateEffect(c)
	e1:SetDescription(aux.Stringid(id,0))
	e1:SetCategory(CATEGORY_ATKCHANGE+CATEGORY_DEFCHANGE)
	e1:SetType(EFFECT_TYPE_SINGLE+EFFECT_TYPE_TRIGGER_F)
	e1:SetCode(EVENT_BATTLE_START)
	e1:SetCondition(s.adcon)
	e1:SetOperation(s.adop)
	c:RegisterEffect(e1)
end
function s.adcon(e,tp,eg,ep,ev,re,r,rp)
	local c=e:GetHandler()
	local bc=c:GetBattleTarget()
	return bc and bc:IsFaceup() and bc:IsType(TYPE_PENDULUM)
end
function s.adop(e,tp,eg,ep,ev,re,r,rp)
	local c=e:GetHandler()
	if c:IsRelateToEffect(e) and c:IsFaceup() then
		local e1=Effect.CreateEffect(c)
		e1:SetType(EFFECT_TYPE_SINGLE)
		e1:SetCode(EFFECT_SET_DEFENSE_FINAL)
		e1:SetValue(c:GetDefense()/2)
		e1:SetReset(RESET_EVENT|RESETS_STANDARD_DISABLE|RESET_PHASE|PHASE_DAMAGE)
		c:RegisterEffect(e1)
		local e2=e1:Clone()
		e2:SetCode(EFFECT_SET_ATTACK_FINAL)
		e2:SetValue(c:GetAttack()/2)
		c:RegisterEffect(e2)
	end
end