declare fun {PartialSums List} fun {Help List Acc} case List of nil then Acc | nil [] X|Xs then local UB in thread UB = {Help Xs Acc+X} end Acc | UB end end end in {Help List 0} end A B C A = 1|B thread {Browse {PartialSums A}} end B = 2|3|4|5|C C = nil