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The short answer to your general question is "no." If the subsection is titled the same as the section, then either one of them is named incorrectly or else your outline is incorrect. An outline ...
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The short answer to your general question is "no." If the subsection is titled the same as the section, then either one of them is named incorrectly or else your outline is incorrect. An outline is supposed to be like this: Title: Great Cities of the World I. American Cities A. Large Cities 1. New York, NY 2. Chicago, IL B. Historical Cities 1. Philadelphia, PA 2. San Diego, CA II. European Cities etc. etc. etc. In mathematical terms: Every subsection must be a _limited_ subset of the section in which it occurs. Corollary One: A section must not be divided into subsections unless there are at least two subsections. Corollary Two: A section name is implicitly part of all subsection names beneath it. Corollary Three: If explicitly adding the section name to a subsection name would cause the subsection name to not make sense, then the subsection is in the wrong section. To answer your specific question: The subsection should be named "Basic Properties."