Indeed, for a given specific energy it is extremely difficult, if not impossible, to check its rank-one convexity which is a necessary and sufficient condition for hyperbolicity of the governing equations.
The first was that the conclusion was not only uncheckable but was such that it was logically impossible to check up on it.
But the difference here is not one of degree but of kind: "in the sense in which it is impossible to check an infinite number of propositions it is also impossible to try to do so" (PG 452).
Mr. Walker said the need to distribute aid rapidly after the storms made it impossible to check out claims initially.
Equifax, meanwhile, says the need to give its customers swift access to its database and the volume of searches conducted would make it impossible to check every inquiry.
The liquid sodium coolant, heated to almost 400 degrees Fahrenheit, makes it impossible to check fully for any damage the device may have caused to the reactor vessel, however.
Voter lists were distributed too late to be posted in most areas, making it impossible to check who had voted, though the use of indelible ink on voters' fingers helped guard against double voting, the European Union mission found.
And in fact, they counted those votes, even though the way the canvassing board dealt with them was to go back and mark them all over with a big black marker, which made it impossible to check whether the canvassing board had really just marked over the ballot or had put a new mark on the ballot.
The Coinbase app was hanging for many — making it impossible to check an account balance let alone buy into The Next Great Bitcoin Rush — and its web-based service didn't fare any better.
Moreover, the complicated way in which the random effects enter a nonlinear mixed model makes it impossible to check the assumption of normality of the errors.
