🌙

☰

Tree (set theory)

In set theory, a tree is a partially ordered set ( T , < ) {\displaystyle (T,<)} such that for each t ∈ T {\displaystyle t\in T} , the set { s ∈ T : s < t } {\displaystyle \{s\in T:s<t\}} is well-ordered by the relation < {\displaystyle <} . Frequently trees are assumed to have only one root (i.e. minimal element), as the typical questions investigated…

Art, Set-theoretic properties & Definition