Undoubtedly then I am in a clear error.
"In that case, I would be totally astray.
Surely, I should then be in clear error
Then I shall surely be in clear error
That I am then in (E) clear/evident misguidance
“I will be totally wrong by doing so.”
“Undoubtedly, I am then in open error.”
`In that case I should, indeed, be in manifest error
Then, certainly, I would be in open error
`Surely, in case (I do anything of the kind) I should be (falling) in (to) a clear error
"Then verily, I should be in plain error