Generate a YGOPro Lua script for the following Yu-Gi-Oh card effect:
Cannot be Special Summoned. Requires 3 "Steelswarm" Tributes to Normal Summon (cannot be Normal Set). Once per turn: You can pay half your Life Points; destroy all other cards on the field.
--インヴェルズ・グレズ
--Steelswarm Hercules
local s,id=GetID()
function s.initial_effect(c)
	--cannot special summon
	local e1=Effect.CreateEffect(c)
	e1:SetProperty(EFFECT_FLAG_CANNOT_DISABLE+EFFECT_FLAG_UNCOPYABLE)
	e1:SetType(EFFECT_TYPE_SINGLE)
	e1:SetCode(EFFECT_SPSUMMON_CONDITION)
	c:RegisterEffect(e1)
	--tribute limit
	local e2=Effect.CreateEffect(c)
	e2:SetType(EFFECT_TYPE_SINGLE)
	e2:SetCode(EFFECT_TRIBUTE_LIMIT)
	e2:SetValue(s.tlimit)
	c:RegisterEffect(e2)
	--summon with 3 tribute
	local e3=aux.AddNormalSummonProcedure(c,true,false,3,3,SUMMON_TYPE_TRIBUTE,aux.Stringid(id,0))
	local e4=aux.AddNormalSetProcedure(c)
	--destroy
	local e5=Effect.CreateEffect(c)
	e5:SetDescription(aux.Stringid(id,1))
	e5:SetCategory(CATEGORY_DESTROY)
	e5:SetType(EFFECT_TYPE_IGNITION)
	e5:SetRange(LOCATION_MZONE)
	e5:SetCountLimit(1)
	e5:SetCost(s.descost)
	e5:SetTarget(s.destg)
	e5:SetOperation(s.desop)
	c:RegisterEffect(e5)
end
s.listed_series={SET_STEELSWARM}
function s.tlimit(e,c)
	return not c:IsSetCard(SET_STEELSWARM)
end
function s.descost(e,tp,eg,ep,ev,re,r,rp,chk)
	if chk==0 then return true end
	Duel.PayLPCost(tp,math.floor(Duel.GetLP(tp)/2))
end
function s.destg(e,tp,eg,ep,ev,re,r,rp,chk)
	if chk==0 then return Duel.IsExistingMatchingCard(aux.TRUE,tp,LOCATION_ONFIELD,LOCATION_ONFIELD,1,e:GetHandler()) end
	local g=Duel.GetMatchingGroup(aux.TRUE,tp,LOCATION_ONFIELD,LOCATION_ONFIELD,e:GetHandler())
	Duel.SetOperationInfo(0,CATEGORY_DESTROY,g,#g,0,0)
end
function s.desop(e,tp,eg,ep,ev,re,r,rp)
	local g=Duel.GetMatchingGroup(aux.TRUE,tp,LOCATION_ONFIELD,LOCATION_ONFIELD,e:GetHandler())
	Duel.Destroy(g,REASON_EFFECT)
end