Workflow creator : if following taksk are marked completed, then send a email to client.

Workflow creator : if following taksk are marked completed, then send a email to client.

Hi There, as you see in the attachment i created a workflow. Now once this workflow runs my clients get a email everytime a task is closed. What i need is :

If all these tasks are closed, then send a email that we received all of his documents. I geus its somewhere in the Criteria Pattern but i cant seem to find it.