finite set
set that has a finite number of elements
empty set
mathematical set containing no elements
clause
in logic, disjunction of literals
system of equations
finite set of equations to be solved simultaneously (as a logical conjunction), possibly for multiple unknowns
root system
geometric arrangements of points, foundational to Lie theory
contrast set
collection of related items in a schema or ontology
alphabet
non-empty set of symbols or letters that make up strings in a formal language
Boolean domain
set consisting of exactly two elements, interpretable as false and true
system of parameters
in an n-dimensional Noetherian local ring R, a set of elements r₁,r₂, …, rₙ, such that the radical of the ideal generated by them equals the maximal ideal
Covering system
collection of finitely many residue classes whose union contains every integer
finite ring
abstract ring with finite number of elements
finite topological space
topological space with a finite number of points
hereditarily finite set
Finite sets whose elements are all hereditarily finite sets