Díaz-Cano Ocaña, Antonio2023-06-202023-06-2020010022-404910.1016/S0022-4049(00)00089-Xhttps://hdl.handle.net/20.500.14352/57211Let X-0 subset of R-n be an analytic set germ of dimension 2. We study the invariant t(X-0) defined as the least integer t such that any open semianalytic set germ of Xo can be written as a union of t basic open set germs. It is known that 2 less than or equal to t(X-0) less than or equal to 3. In this note we provide a geometric criterion to determine the exact value of t(X-0).engjournal articlehttp://www.sciencedirect.com/science/article/pii/S002240490000089Xhttp://www.sciencedirect.com/restricted access512.7Real analytic setSemianalytic setgermsT-invariantStability indexGeometria algebraica1201.01 Geometría Algebraica