Published online by Cambridge University Press: 03 November 2016
Several writers have studied algebras in which multiplication is non-associative, that is, x yz≠xy z. It is necessary in a non-associative algebra to distinguish the possible interpretations of a power xn In a non-commutative non-associative algebra x 2 is unique, x 3 can mean xx 2 or x 2 x; x 4 can mean x xx 2, x x 2 x, x 2 x 2, xx 2x or x 2 x x, x 5 has 14 interpretations; x 6 has 42; and so on. In a commutative non-associative algebra, the possible interpretations are fewer x 3 is unique, x 4 can mean xx 3 or x 2 x 2, x 5 can mean x xx 3, x x 2 x 2 or x 2 x 3, x 6 has 6 interpretations, and so on. The problem considered here is how many meanings are there for xn (A) in a general non-commutative non-associative algebra ? (B) in a general commutative non-associative algebra ? The answer to (A) is I am not able to find any such simple formula for (B).
page no 36 note * E.g. De Morgan, , Trans. Camb. Phil Soc., 8 (1844), 241 Google Scholar; Dickson, , Trans. Amer. Math. Soc., 13 (1912), 60 CrossRefGoogle Scholar. Jordan, Göttingen Nachr., 1932, 569; 1933, 209, deals with an application to Quantum Mechanics. A forthcoming paper by the author on Genetics uses commutative non-associative algebras.
page no 36 note † Though not in the algebras considered by Jordan.