===== Monoid kernel =====
==== Set ====
| @#55CCEE: context     | @#55CCEE: $ X $ |
| @#55CCEE: context     | @#55CCEE: $ M $ ... monoid |
| @#55CCEE: context     | @#55CCEE: $ f:X\to M $ |

| @#FFBB00: definiendum | @#FFBB00: $ x\in\mathrm{ker}(f) $ |

| @#55EE55: postulate   | @#55EE55: $ f(x)=e $ |

==== Discussion ====
$\mathrm{ker}(f)$ is $\mathrm{sol}(f)$ w.r.t. the unit of the monoid.
=== Reference ===
Wikipedia: [[http://en.wikipedia.org/wiki/Solution_set|Solution set]]
==== Parents ====
=== Subset of ===
[[Solution set]]
=== Context ===
[[Monoid]]