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Stephen Tashi
Jan29-12, 11:46 AM
Sci Advisor
P: 3,285
Quote Quote by robimaru View Post
is there a property of summation that says that when the upper limit is less than the lower limit, its value will be zero?
That is a common convention in summation notation, but if you are writing a proof, you can't justify a step because of a notational convention. If the indicated computation implies that there are no terms of a certain type to sum, you can point that out in words.