Supplementary mathematics/Theory of sets

Set theory is a fundamental branch of mathematics that deals with the study of sets, i.e. combinations of objects. All mathematics as commonly taught is formulated in the language of set theory and is built upon the axioms of set theory. Most mathematical objects that are treated in subareas such as algebra, analysis, geometry, stochastics or topology can be defined as sets. Measured against this, set theory is a fairly young science; only after overcoming the fundamentals crisis in mathematics in the early 20th century was set theory able to take its central and fundamental place in mathematics today.