I suggested an edit a few hours ago, which is approved.
this raises a question in my mind, that is, whether "I'm ready for something" is equal to "I'm prepared for something"
and then another contributor removed the "that is", as a result we have
this raises a question in my mind whether ...
Is it grammatical? What is the structure of it.
"this" functions as a subject; "raises" functions as a predicate; "a question" functions as an object; "in my mind" is an adverbial phrase.
With "that is", the rest is a relative clause; without "that is", what is the rest?