**Acceptance criteria:**

* Begin of the insertionA calculated valueEnd of the insertion Begin of the deletion Factor listEnd of the deletion is added to the available as a project attribute

* The project attribute can be displayed in Begin of the insertion

* End of the insertion the project Begin of the insertionoverview

End of the insertion Begin of the deletion overview.

End of the deletion * Begin of the insertionthe projectEnd of the insertion Begin of the deletion A factorEnd of the deletion list Begin of the insertion

* A calculated valueEnd of the insertion has these details:

* Name

* Formula

* For all projects

* The formulas can include the following attributes from that project:

* Integer

* Float

* Project factors (project attribute factor lists)

* Mathematical operators: +, -, \*, /, /, ( and )

* Other calculated values

* In order to trigger the selection of the attributes in the field, the user can use the command "/" as implemented in the Automatically generated subjects.

* The command triggers a dropdown to open with sections for:

* Mathematical operators

* Project factors

* Calculated values

* Begin of the insertionError handling

* End of the insertion In calculations, there is error handling for Begin of the insertion**circular references**.

End of the insertion Begin of the deletion circular references.

End of the deletion * In case the user includes text that is Begin of the insertion**notEnd of the insertion Begin of the deletion notEnd of the deletion an integer or a Begin of the insertionfloat,**End of the insertion Begin of the deletion float,End of the deletion the field will display an inline error: "Only numeric values, project factors, calculated values and mathematical operators are allowed" Begin of the insertion

End of the insertion Begin of the deletion

End of the deletion * Begin of the insertionIn case the mathematical operation fails (e.g. becauseEnd of the insertion Begin of the deletion OrderEnd of the deletion of Begin of the insertiona **division by zero error**), the field will display an inline error.

* **Open question**: are the factor list attributes required? If they _could_ be empty, we must consider error handling. For example, if the formula contains any attributes that are not set, the field will display an inline error: "The attributes foo and bar are not set. Please set all attributes required for the calculation."

* **Order of operations:**End of the insertion Begin of the deletion operations:End of the deletion Automatic application of the mathematical rule where multiplication and division are performed before addition and subtraction, unless parentheses dictate otherwise