دَحْرَجْتُهُ فَتَدَحْرَجَ
Translation: I rolled it, so it rolled away.
This is the book's straightforward example of Tafaʿlala showing the outcome of Faʿlala.
Initiating formResulting form
دَحْرَجْتُهُفَتَدَحْرَجَ
I caused it to rollIt rolled
Faʿlala actionTafaʿlala outcome
The entity affected in the first clause is the one whose resulting state appears in the second.