Definiciones
1.NounThe finite topological space X consisting of four distinct points { a, b, c, d } with the non-Hausdorff topology
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{\displaystyle \left\{\{a,b,c,d\},\{a,b,c\},\{a,b,d\},\{a,b\},\{a\},\{b\},\emptyset \right\}}
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