The phrase "a concrete proof of" is correct and usable in written English.
It can be used when referring to tangible evidence or a definitive example that supports a claim or argument.
Example: "The scientist presented a concrete proof of the theory through extensive experimentation and data analysis."
Alternatives: "a solid evidence of" or "a definitive proof of".
Likewise in Weir's version of game formalism, what makes true (or false) "sin2θ + cos2θ = 1" in a particular system is the existence of a concrete proof or refutation, though the statement that such a concrete proof exists is no part of the literal meaning or sense of the claim.
Andreoli originally discovered focalization as a concrete proof search strategy in proof theory of linear logic, putting to the foreground the role of polarity in logic.
The demonstration proceeds with a generalisation over all numbers k which number the axioms in a concrete proof and then performs a sequence of selections on them.
The incorporation of major tolerance of complete submergence into varieties already grown on millions of hectares is a concrete proof that this opportunity can be translated into reality [10].
A demonstration or concrete proof of the antecedent, be it an actual or a hypothetical one, is required to obtain a canonical form.
The growing evidence that Prince Mohammed was involved in the killing of Mr. Khashoggi is certain to intensify pressure on the White House, which appeared intent on relying on a lack of concrete proof of his involvement to preserve its relationship with the crown prince.
This measurement offers, for the first time, a direct and concrete proof of correct in situ synthesis of RNA microarrays.
"The question is, will the Israelis hit Iran?" Mohamed ElBaradei, the I.A.E.A. director, has repeatedly stated that his agency has not "seen concrete proof of a military program, so it's premature to make a judgment on that".
Yet they still say officially they have no concrete proof of a weapons programme.
