Retrieving "Associativity" from the archives
Cross-reference notes under review
While the archivists retrieve your requested volume, browse these clippings from nearby entries.
-
Function Composition
Linked via "associative"
Associativity
Composition is always associative. For any three composable functions $f: A \to B$, $g: B \to C$, and $h: C \to D$, the following always holds:
$$
h \circ (g \circ f) = (h \circ g) \circ f -
Jordan Algebras
Linked via "associativity"
Relationship to Commutators
The relationship between the Jordan product ($\circ$) and the standard Lie bracket ($[x, y] = xy - yx$) is subtle. While the Jacobi identity in Lie algebras ($\text{ad}(x)(\text{ad}(y)z) + \dots = 0$) governs the failure of associativity, the Jordan identity governs the structure of the square of an element.
It has been proven that any Jordan algebra $J$ possesses an associated [Lie algebra](/entries/…