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## Mathematical Structures

The webpages collected here list information about classes of mathematical structures. The aim is to have a central place to check what properties are known about these structures.

*These pages are currently still under construction. Knowledgeable readers are encouraged to add or correct information.* To enable the edit button on each page, use the Login link (below) to enter a Username of your choice and the password “mathstruct”.

Initially the main content concerns mostly first-order classes of relational structures and, more particularly, varieties of universal algebras. If you are familiar with some of these classes of structures, feel free to add some relevant information and references by using the edit link on the respective page. Most pages are written in standard LaTeX (if you don't know LaTeX you should probably not edit these pages – the previous non-LaTeX version of these pages is still available at http://math.chapman.edu/cgi-bin/structures.pl ). You can use this Sandbox page to try out editing (without worrying about deleting useful information).

Suggestions or comments? Just follow the link and edit the page.

This front page can also be edited to add further classes of structures. A criterion for inclusion in this list is that there should be some journal publication or book where the class has been named and defined.

Acknowledgements | Notation and terminology | Properties | Tools | Online books and lecture notes

Varieties | Quasivarieties | Universal classes | First-order classes | Second-order classes | Logics

#### Alphabetical list of all classes

Trace: » start