- Megrez (stars.astro.illinois.edu)
MEGREZ (Delta Ursae Majoris). The faintest star of the Big Dipper, Megrez is in the Dipper’s middle, linking the handle to the bowl, and in the bigger picture linking Ursa Major’s tail to the Bear’s hindquarters. The name appropriately refers not to the Dipper, but to the Bear, and straightforwardly comes from a long Arabic phrase that means the root of the Great Bear’s tail.
- Associative property (Wikipedia)
In mathematics, the associative property is a property of some binary operations, which means that rearranging the parentheses in an expression will not change the result. In propositional logic, associativity is a valid rule of replacement for expressions in logical proofs.