The phrase "at all erroneous" is correct and usable in written English.
It can be used to emphasize that something is completely incorrect or false.
Example: "The report was not at all erroneous; every detail was meticulously verified."
Alternatives: "completely incorrect" or "entirely false".
I think he nailed some of the problems, but arrived at an erroneous conclusion.
One patient enrolled at dose level 5 was treated with etoposide at an erroneous dose of 100 mg m−2 for 3 days during the first cycle and at the correct dose during subsequent cycles.
"Expecting to determine 'the precise location of the aircraft' before continuing the search was at best an erroneous expectation and at worst a clever formulation to bury the search.
Animals did not show perseveration after errors (i.e., responding again at the erroneous location).
We will also look at some erroneous concepts of the brain in popular culture, and compare this to the level of detail present in the scientific source material.
In further aid of that contention, Inc. argues that the CRC's and Lazard's stated view that the price the Barclays are paying is a tremendous one are, at best, erroneous and, at worst, disingenuous.
Regarding contingent facts, then, the same opinion or the same statement comes to be false and true, and it is possible for it to be at one time correct and at another erroneous; but regarding things that cannot be otherwise opinions are not at one time true and at another false, but the same opinions are always true or always false.
It is noteworthy that solving the nonlinear equation system at very erroneous initial estimations may lead to quite different results or lack of convergence.
The agency's delisting decision was "fatally flawed," she wrote, because it was tied to "a scientific finding that turned out to be, at best, premature, or, at worst, erroneous".
This month, it's easy to arrive at the erroneous conclusion that having adult ADHD is no big deal.
