incontrovertibly

kiistattomasti In an incontrovertible manner; in a manner not capable of being denied, challenged, or disputed.
1810, Thomas Comber, Adultery Analyzed: an inquiry into the causes of the prevalence of that vice, page 19

It is, incontrovertibly, our duty, if divine and civil laws have given us a rule whereby to regulate our conduct, and which may both promote the benefit of society and the good of the individual, we are obliged to act agreeably to that rule, let the conduct of others be what it may.

In such a case and under such proof the intent to kill and the deliberate and premeditated malice are incontrovertibly implied.

And if word did spread that he had withdrawn his money from the bank in cash, every man and his cousin in the county would be his threat and enemy until every one of them was incontrovertibly convinced that the actual money actually was somewhere else, and exactly where that somewhere else was.