Sentence examples for are formally valid from inspiring English sources

Only LVFs are formally valid, and their validity depends only on the definitions of the logical operators used within Zsyntax, regardless of the molecules involved.

According to this conception, different formal languages will be useful in modeling the inferences that are formally valid given different set of 'logical constants' or expressions whose meaning is kept fixed.

If the two original arguments are formally valid, then so too is the longer argument from three premises.

Such a claim may have been formally valid, but there may have also been underlying political considerations.

And when an inference is formally valid then the conclusion logically follows from the premises.

4. One way to answer the challenge would be to (try to) deny that the inference considered is formally valid.

Perhaps to say that an argument is formally valid is to say that it falls under some general scheme of which every instance is valid, such as Ferio.

There is another way in which conclusions can be necessary and relevant to their premisses, yet not be formally valid (not be a complete entailment).

An argument is formally valid if and only if, no matter how the non-logical vocabulary is interpreted, the premises cannot be true and the conclusion false.

But (b) given our intuitive anti-skepticism, C seems immensely implausible, even though (c) the argument appears to be formally valid.

Thus, although the syllogism, 'Nothing dead is an animal, some man is dead; therefore, some man is not an animal', is an acceptable fourth-mode syllogism of the first figure (Ferio), Buridan denies that the consequence is "formally valid".