- In mathematics, a
binary relation R is
called well-founded (or
wellfounded or foundational) on a set or, more generally, a
class X if
every non-empty...
- In set theory, an
ordinal number, or ordinal, is a
generalization of
ordinal numerals (first, second, nth, etc.)
aimed to
extend enumeration to infinite...
- In mathematics, Kruskal's tree
theorem states that the set of
finite trees over a well-quasi-ordered set of
labels is
itself well-quasi-ordered
under homeomorphic...
- In mathematics, the well-ordering
principle states that
every non-empty
subset of
nonnegative integers contains a
least element. In
other words, the set...
- Kőnig's
lemma or Kőnig's
infinity lemma is a
theorem in
graph theory due to the
Hungarian mathematician Dénes Kőnig who
published it in 1927. It gives...
-
Structural induction is a
proof method that is used in
mathematical logic (e.g., in the
proof of Łoś' theorem),
computer science,
graph theory, and some...
- In set theory, a
universal set is a set
which contains all objects,
including itself. In set
theory as
usually formulated, it can be
proven in multiple...
- In mathematics, a
simple subcubic graph (SSCG) is a
finite simple graph in
which each
vertex has a
degree of at most three.
Suppose we have a sequence...
- In mathematics, the
ascending chain condition (ACC) and
descending chain condition (DCC) are
finiteness properties satisfied by some
algebraic structures...
-
theory obtained by
removing the
axiom of
regularity from ZFC.
Various non-
wellfounded set
theories allow "safe"
circular sets, such as
Quine atoms, without...
