Changes

A [[tree structure]] is a way of representing the hierarchical nature of a structure in a graphical form. It is named a "tree structure" because the graph looks a bit like a tree, even though the tree is generally shown upside down compared with a real tree; that is to say with the root at the top and the leaves at the bottom. In mathematical logic, a [[Structure (mathematical logic)|structure]] is an object that gives semantic meanings to the symbols in a logical language. The most common setting is with first-order languages, but structures for typed and higher-order languages are also important. In universal algebra, a branch of pure mathematics, an [[algebraic structure]] consists of one or more sets closed under one or more operations, satisfying some axioms. Abstract algebra is primarily the study of algebraic structures and their properties.

A [[tree structure]] is a way of representing the hierarchical nature of a structure in a graphical form. It is named a "tree structure" because the graph looks a bit like a tree, even though the tree is generally shown upside down compared with a real tree; that is to say with the root at the top and the leaves at the bottom. In mathematical logic, a [[Structure (mathematical logic)|structure]] is an object that gives semantic meanings to the symbols in a logical language. The most common setting is with first-order languages, but structures for typed and higher-order languages are also important. In universal algebra, a branch of pure mathematics, an [[algebraic structure]] consists of one or more sets closed under one or more operations, satisfying some axioms. Abstract algebra is primarily the study of algebraic structures and their properties.

==Chemistry==

==Chemistry==