In case Kuci's explanation isn't clear, then here is an example :
Used with the mentioned compiler it will give 5.187...
Code:
begin integer i; real procedure sum (i, lo, hi, term); value lo, hi; integer i, lo, hi; real term; comment term is passed by-name, and so is i; begin real temp; temp := 0; for i := lo step 1 until hi do temp := temp + term; sum := temp end; print (sum (i, 1, 100, 1/i)) end
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