===== Trace of square matrices =====
==== Set ====
| @#55CCEE: context     | @#55CCEE: $n\in \mathbb N$ | 
| @#55CCEE: context     | @#55CCEE: $M$ ... abelian monoid | 

| @#FFBB00: definiendum | @#FFBB00: $ \mathrm{tr}:\mathrm{SquareMatrix}(n,M)\to M$ |
| @#FFBB00: definiendum | @#FFBB00: $ \mathrm{tr}(A):=\sum_{k=1}^n A_{kk}$ |

==== Discussion ====
=== Reference ===
Wikipedia: [[http://en.wikipedia.org/wiki/Trace_%28linear_algebra%29|Trace (linear algebra)]]
==== Parents ====
=== Context ===
[[Abelian monoid]], [[Square matrix]], [[Finite sum over a monoid]]