User interface > Debugging and executing > Choosing a start rule
To transform a text, you first have to choose a start rule. This choice is done in the according combo box of the tool bar:
Per default the production, which is set in the project options, will be selected in the combo box of the tool bar. If there is no explicit start rule set in the options, the name of the production will be displayed, which also is the name of the project. If there is no such rule, the selection remains empty and you have to choose a production manually.
Even productions with parameters, can be chosen as start rule. When such a rule is executed, default values are used for the parameters.