Topic: Sets, Functions and Relations for Topology

Why Images Do Not Preserve Complements

Unions, Intersections, and Set Difference

Subsets, Equality, and Double Inclusion

Set Membership and Set-Builder Notation

Relations as Subsets of Cartesian Products

Relative Complements and De Morgan’s Laws

Preimage Identities and Their Proofs

Partitions and Equivalence Relations

Injectivity and Surjectivity Through Set Images

Indexed Families of Sets