set theory


Definition of set theory

: a branch of mathematics or of symbolic logic that deals with the nature and relations of sets

Keep scrolling for more

Other Words from set theory

set theoretic adjective

Examples of set theory in a Sentence

Recent Examples on the Web This past July, Malliaris and Shelah were awarded the Hausdorff medal, one of the top prizes in set theory. Quanta Magazine, "Mathematicians Measure Infinities and Find They’re Equal," 12 Sep. 2017 Family-friendly activities focusing on basic operations of numbers, set theory, mappings, two- and three-dimensional geometry and probability will be offered. Houston Chronicle, "Nov. 8-16: Holiday events, craft fairs planned in northwest Harris County," 31 Oct. 2019 The logicians spoke the languages of their respective specialties — set theory and theoretical computer science — in expressing these ideas. Quanta Magazine, "Why the Proof of Fermat’s Last Theorem Doesn’t Need to Be Enhanced," 3 June 2019 The accepted foundation of mathematics is set theory. Quanta Magazine, "Will Computers Redefine the Roots of Math?," 19 May 2015 Another approach that aims to reconcile the apparent passage of time with the block universe goes by the name of causal set theory. Quanta Magazine, "A Debate Over the Physics of Time," 19 July 2016 Malliaris and Shelah published their proof last year in the Journal of the American Mathematical Society and were honored this past July with one of the top prizes in the field of set theory. Quanta Magazine, "Mathematicians Measure Infinities and Find They’re Equal," 12 Sep. 2017 Their breakthrough, proved over 60 pages of complex calculations, was in applying one field known as model theory to another field called set theory. The Christian Science Monitor, "The awards and rewards of grasping infinity," 19 Sep. 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'set theory.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

See More

First Known Use of set theory

1936, in the meaning defined above

Keep scrolling for more

Learn More about set theory

Time Traveler for set theory

Time Traveler

The first known use of set theory was in 1936

See more words from the same year

Statistics for set theory

Cite this Entry

“Set theory.” Dictionary, Merriam-Webster, Accessed 10 Jul. 2020.

More from Merriam-Webster on set theory

Britannica English: Translation of set theory for Arabic Speakers Encyclopedia article about set theory

Comments on set theory

What made you want to look up set theory? Please tell us where you read or heard it (including the quote, if possible).


See Definitions and Examples »

Get Word of the Day daily email!

Test Your Vocabulary

Words for Summer: A Quiz

  • a closeup of a sunflower
  • Which of the following words means “of or relating to summer”?
Spell It

Can you spell these 10 commonly misspelled words?

Dictionary Devil

Test Your Knowledge - and learn some interesting things along the way.

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!