most recent 30 from http://mathoverflow.net 2013-06-20T06:38:17Z http://mathoverflow.net/feeds/user/23897 http://www.creativecommons.org/licenses/by-nc/2.5/rdf http://mathoverflow.net/questions/97727/question-about-reflective-subcategory yeliz 2012-05-23T08:11:35Z 2012-05-23T08:11:35Z

<p>Hello everyone, I want to ask a question but forgive me if it is so simple.</p> <p>Consider the poset of natural numbers as a category, B. Verify that a subset A of B, considered as full subcategory of B, is</p> <p>• reflective in B if and only if A is infinite, • coreflective in B if and only if 0 is element of A.</p> <p>Thanks any advance.. </p>