Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
Any monster that is Normal Summoned, Flip Summoned or Special Summoned is changed to Defense Position.
--つまずき
--Stumbling
local s,id=GetID()
function s.initial_effect(c)
	--Activate
	local e1=Effect.CreateEffect(c)
	e1:SetType(EFFECT_TYPE_ACTIVATE)
	e1:SetCode(EVENT_FREE_CHAIN)
	c:RegisterEffect(e1)
	--pos
	local e2=Effect.CreateEffect(c)
	e2:SetDescription(aux.Stringid(id,0))
	e2:SetCategory(CATEGORY_POSITION)
	e2:SetType(EFFECT_TYPE_FIELD+EFFECT_TYPE_TRIGGER_F)
	e2:SetCode(EVENT_SUMMON_SUCCESS)
	e2:SetRange(LOCATION_SZONE)
	e2:SetTarget(s.target)
	e2:SetOperation(s.operation)
	c:RegisterEffect(e2)
	local e3=e2:Clone()
	e3:SetCode(EVENT_FLIP_SUMMON_SUCCESS)
	c:RegisterEffect(e3)
	local e4=e2:Clone()
	e4:SetCode(EVENT_SPSUMMON_SUCCESS)
	c:RegisterEffect(e4)
end
function s.target(e,tp,eg,ep,ev,re,r,rp,chk)
	if chk==0 then return e:GetHandler():IsRelateToEffect(e) end
	Duel.SetTargetCard(eg)
	Duel.SetOperationInfo(0,CATEGORY_POSITION,eg,#eg,0,0)
end
function s.filter(c,e)
	return c:IsFaceup() and c:IsAttackPos() and c:IsRelateToEffect(e)
end
function s.operation(e,tp,eg,ep,ev,re,r,rp)
	if not e:GetHandler():IsRelateToEffect(e) then return end
	local g=eg:Filter(s.filter,nil,e)
	Duel.ChangePosition(g,POS_FACEUP_DEFENSE)
end