This evaluation type checks if the variable in the Definition field is present in the operator of the Definition field. i.e. `times,x`

checks whether there is a multiplication that has a variable x as a descendant in the student’s answer. Example:

The second argument in the Definition can be a list, where multiple variables can be searched with an OR. For example, the following rule checks whether there is a division that has x or y as a descendant.

An optional third argument in the Definition specifies the position of the child. For example, the following rule checks whether the denominator (and not the numerator) of a fraction has an x or y in it.

Moreover, this rule checks whether there is an x in the left argument of a multiplication:

❗ Note: if your feedback rule doesn’t seem to work for some reason, try deleting any spaces in the feedback Definition.

**Automated feedback**

Below are some examples of what the automated feedback of this evaluation type looks like:

**More on evaluation types**

An overview of all evaluation types can be found here (for mathematical answers) and here (for text-based answers). More detail on the different fields of a feedback rule can be found here.