ThmDex – An index of mathematical definitions, results, and conjectures.
Set of symbols
Alphabet
Deduction system
Theory
Zermelo-Fraenkel set theory
Set
Binary cartesian set product
Binary relation
Binary endorelation
Preordering relation
Partial ordering relation
Partially ordered set
Minimal element
Minimum element
Set lower bound
Set of lower bounds
Definition D301
Infimum element
Formulation 0
Let $P = (X, {\preceq})$ be a D1103: Partially ordered set.
Let $\mathsf{LB} = \mathsf{LB}_P(E)$ be the D553: Set of lower bounds of $E \subseteq X$ with respect to $P$.
A D2218: Set element $x_0 \in X$ is an infimum of $E$ with respect to $P$ if and only if
(1) $x_0 \in \mathsf{LB}$
(2) $\forall \, x \in \mathsf{LB} : x \preceq x_0$
Formulation 1
Let $P = (X, {\preceq})$ be a D1103: Partially ordered set.
Let $\mathsf{LB} = \mathsf{LB}_P(E)$ be the D553: Set of lower bounds of $E \subseteq X$ with respect to $P$.
A D2218: Set element $x_0 \in X$ is an infimum of $E$ with respect to $P$ if and only if
(1) $x_0 \in \mathsf{LB}$
(2) $\forall \, x \in \mathsf{LB} : (x, x_0) \in {\preceq}$