(sec-theory)=
# Theory and formulations

This section includes some material on formulations and general theoretical backgrounds for Exudyn.
Note that the formulation of nodes, objects, markers, etc. is presented right at the subsection of each object, see {ref}`sec-item-reference-manual`.
Furthermore, the general notations are described in {ref}`sec-generalnotation` and an overview on the system assembly and system equations of motion is given in {ref}`sec-generalnotation`, solvers are described in {ref}`sec-solvers`.

```{toctree}
:maxdepth: 2

theoryMultibody
theoryDynamics
theoryRotations
theoryFEM
theoryModal
theoryContact
```