line6,each is the one-step updated parameter for each task, which would not be used as parameters for testing. Instead, it is used to update , which is the final initilization that we wish to get.
This way, it is asctually minimizing the average loss across different tasks after one-step update. In other word, MAML could find the initilization parameters that is optimal for training with only one step update.
Line 4-8 could be expressed equivalently as follow: