Mathematics Topology is a branch of mathematics focused on the properties of space that are preserved under continuous transformations, such as stretching, twisting, crumpling, and bending, without tearing or gluing. It explores concepts like continuity, compactness, and connectedness, and employs algebraic structures to study the qualitative aspects of geometric spaces. Topology has applications across various fields, including analysis, geometry, and even in areas such as robotics, computer science, and physics, where understanding the properties of space is essential.

General Concepts Topological Spaces Definition of a Topological Space Set theory preliminaries Axiomatization of topologies Distinction from metric and other spaces Open Sets Definition and examples Characteristics of open sets in different topologies Open set operations (unions, intersections) Closed Sets Definition and examples De Morgan’s laws relating open and closed sets Operations: complements and closures Basis for a Topology Definition and purpose of a basis Examples in standard topologies (Euclidean and discrete) How bases generate a topology Basis comparison: finer vs coarser topologies Subbasis Definition and generating a topology from subbases Relationship to basis and open sets Subbases in common topological spaces Interior, Closure, and Boundary Definition of interior: Int(A) Properties and examples of interiors Definition of closure: Cl(A) Characteristics and examples of closures Boundary definition and its relationship to interior and closure Examples illustrating interior, closure, and boundary in different spaces Continuous Functions Definition of Continuity Topological vs metric continuity Preimage characterization of continuity Examples illustrating continuous and discontinuous functions Homeomorphisms Definition and characteristics Examples of homeomorphic and non-homeomorphic spaces Significance in classifying spaces Topological Invariants Definition and purpose Examples: connectivity, compactness, dimension How invariants help classify spaces Convergence Nets Definition and need for generalizing sequences Characteristics of convergent nets Examples illustrating nets in different spaces Filters Definition and motivation Relationship between filters and convergence Examples of filters in topological spaces Comparison to nets and sequences Role in understanding compactness and continuity