Exercise · ZW-LATTICE-OR-ORDER-THEORY-001 · ★☆☆ Basic

What is the supremum of 4 and 6 in the poset of divisors of 12 ordered by divisibility?

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  • C. 12

Explanation

The supremum is the least common upper bound; 12 is a multiple of both 4 and 6 and is the smallest such divisor of 12.

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Review the concept: Lattice or order theory

A lattice is a partially ordered set (L, ≤) in which every pair of elements x and y has a supremum (x ∨ y) and an infimum (x ∧ y).

\[x \vee y = \sup\{x,y\}, \quad x \wedge y = \inf\{x,y\}\]

More practice problems: lattice or order theory

ZW-LATTICE-OR-ORDER-THEORY-002 →