Even Fibonacci numbers

 --Each new term in the Fibonacci sequence is generated by adding the previous two terms. By starting with 1 and 2, the first 10 terms will be:
 --1, 2, 3, 5, 8, 13, 21, 34, 55, 89, ...
 --By considering the terms in the Fibonacci sequence whose values do not exceed four million, find the sum of the even-valued terms.
 function list_iter()
     local n =
     local i =
     local j =
     return function()
         if(i < n) then
             tmp = i + j
             j = i
             i = tmp
             return i
         end
     end
 end

 local sum = ;
 for i in list_iter() do
     if(i %  == ) then sum = sum + i end
 end
 print(sum)