👉 In mathematics, an extratension is a specific type of extension that can be used in algebraic geometry to construct new varieties. In this context, "extratension" refers to the construction of new varieties by adding additional parameters to an existing one. An extratension has two main properties: 1. It requires an extra set of parameters. 2. It is a topological invariant, meaning that it can be used in algebraic geometry and topology to construct new varieties. For example,
