**Mandatory element**

A notation is the basic nomenclature of any system or subsystem inside MOSAICmodeling. Complex equation systems or models may have several connected notations. However, let us begin with a single notation here. The more complex case of several notations will be discussed in the section on connectors.

### Purpose

Every variable element that you use in your equations, must be introduced in a notation. This shall inform the choice of your variable names and makes sure that you think about the names of each variable. A variable inside MOSAICmodeling may consist of up to four different parts:

- Base names
- Superscripts
- Subscripts
- Indices

Each variable may only have one Base Name and one Subscript, but as many Superscripts and Indices as required:

### Explanation of the editor

Base Names, Superscripts, Subscripts, and Indices for all variables appearing within your Equation System need to be entered into your Notation with the help of the Notation editor (Figure 1). Table 1 explains the entries of the notation editor.

Element | Explanation |
---|---|

File | Filename of your notation once you have saved or loaded it |

Unit set | Filename of your loaded unit set |

Description | Description of your notation, e.g., its purpose. A description is always necessary |

Keywords | Optional keywords for your notation |

Base names | All base names of your notation |

Superscripts | All superscripts of your notation |

Subscripts | All subscripts of your notation |

Indices | All indices of your notation |

Index (in adding window) | When you click on the plus at the bottom right corner, and adding window opens. Here you need to add the index (or the another variable element) |

Max. value (in adding window) | In the case of an index, you need to set the variable that determines the maximum value of this index so that you can, for example, in sum formulation |

Description (in adding window) | A short description of the index, e.g., “component index” |

### Workflow

The image below illustrates the workflow to set up a whole notation.