Yes, you're correct on both counts. "
New words, one handy idiom, and a 2-minute quiz — delivered to your inbox to keep your streak alive.
AnonymousIs "that" an anaphoric substitute of the main clauseYes.
Anonymousis "no doubt" in extraposition relation with "of that"I'd say it was a simple inversion of the usual word order. The base sentence is There is no doubt of that, and 'of that' is moved to the initial position.