👉 In mathematics and topology, a sublieutenancy of a topological space is a subset that can be considered as an intersection of open sets. A sublieutenancy may be defined by specifying a condition on the elements in the space, such as being closed under certain operations or forming an equivalence relation. For example, consider the following set: \[ X = \{ (x_1, y_1) | x_1^2 + y_1^2 < 1 \
