Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
2 Level 4 monsters Once per turn: You can detach 1 Xyz Material from this card to activate 1 of these effects; ● Send 1 card from your Deck to the Graveyard. ● Choose 1 monster from your Deck and place it on top of your Deck.
--ラヴァルバル・チェイン
--Lavalval Chain
local s,id=GetID()
function s.initial_effect(c)
	c:EnableReviveLimit()
	--Xyz Summon procedure
	Xyz.AddProcedure(c,nil,4,2)
	--Activate 1 of these effects
	local e1=Effect.CreateEffect(c)
	e1:SetDescription(aux.Stringid(id,0))
	e1:SetType(EFFECT_TYPE_IGNITION)
	e1:SetRange(LOCATION_MZONE)
	e1:SetCountLimit(1)
	e1:SetCost(Cost.DetachFromSelf(1,1,nil))
	e1:SetTarget(s.efftg)
	e1:SetOperation(s.effop)
	c:RegisterEffect(e1)
end
function s.efftg(e,tp,eg,ep,ev,re,r,rp,chk)
	local b1=Duel.IsExistingMatchingCard(Card.IsAbleToGrave,tp,LOCATION_DECK,0,1,nil)
	local b2=Duel.GetFieldGroupCount(tp,LOCATION_DECK,0)>1
		and Duel.IsExistingMatchingCard(Card.IsMonster,tp,LOCATION_DECK,0,1,nil)
	if chk==0 then return b1 or b2 end
	local op=Duel.SelectEffect(tp,
		{b1,aux.Stringid(id,1)},
		{b2,aux.Stringid(id,2)})
	e:SetLabel(op)
	if op==1 then
		e:SetCategory(CATEGORY_TOGRAVE)
		Duel.SetOperationInfo(0,CATEGORY_TOGRAVE,nil,1,tp,LOCATION_DECK)
	elseif op==2 then
		e:SetCategory(0)
	end
end
function s.effop(e,tp,eg,ep,ev,re,r,rp)
	local op=e:GetLabel()
	if op==1 then
		--Send 1 card from your Deck to the GY
		Duel.Hint(HINT_SELECTMSG,tp,HINTMSG_TOGRAVE)
		local g=Duel.SelectMatchingCard(tp,Card.IsAbleToGrave,tp,LOCATION_DECK,0,1,1,nil)
		if #g>0 then
			Duel.SendtoGrave(g,REASON_EFFECT)
		end
	elseif op==2 then
		--Place 1 monster from your Deck on top of your Deck
		local ct=Duel.GetFieldGroupCount(tp,LOCATION_DECK,0)
		if ct==0 then return end
		if ct==1 then return Duel.ConfirmDecktop(tp,1) end
		Duel.Hint(HINT_SELECTMSG,tp,aux.Stringid(id,3))
		local tc=Duel.SelectMatchingCard(tp,Card.IsMonster,tp,LOCATION_DECK,0,1,1,nil):GetFirst()
		if tc then
			Duel.ShuffleDeck(tp)
			Duel.MoveSequence(tc,0)
			Duel.ConfirmDecktop(tp,1)
		end
	end
end