The rules of mathematical logic classify a vacuous truth as being true. Therefore, if I say "All of my answers with score >500 have been accepted," that is a true statement according to the rules of logic.
Does Judaism acknowledge this kind of statement as being either true or false? Would מדבר שקר תרחק tell me to avoid making such statements?
I don't know.
But here's an argument possibly supporting allowing making such statements: The Torah discusses the case of a ben sorer umore (a rebellious son). The Talmud (Sanhedrin 71 amud 1] cites an opinion that such a case has never happened and never will. Nonetheless, the Torah discusses what to do if it does happen. That is, the Torah itself is engaging in a sort of vacuous-hypothesis truthtelling.
While this blog post is not a definitive answer, he cites Ramba"m's statements at the beginning of Hilchot Yesodei Hatorah, pointing out how Ramba"m uses the word "Emet" in various ways that go beyond the common translation as "truth". Excerpt:
The Rambam here is not talking about what is True, but about what is Real.
Aside from general accuracy, I think that the difference between the different translations is profound. 'Truth' is an abstract concept that we essentially borrowed from the Greeks. They invented or discovered (not getting into that here) logical rules and postulates which allowed them to categorize statements as being 'true' or 'false'. Something which is 'True' corresponds to some kind of Ideal Form, and something which is false does not.
At some point, the Hebrew terms 'emet' and 'sheker' came to correspond to these Greek concepts. As we got used to the Greek way of thinking, it was important to have the vocabulary to communicate it. The problem is obviously that it ends up 'Hellenizing' ideas and statements that appear in early Jewish works. Those early sources are not necessarily concerned with abstractions. The Torah and the Neviim, and Chaza"l in their wake, are amazingly concrete, often expressing abstraction in very 'earthy' ways. They were interested in what's real and what's fake, what's authentic and what's phony, what's original and what's imitation. The problem with lying is not the violation of some abstract category, but the representation of something which is misleadingly non-real.
As a supporting idea, you often see the term "Emet" following "Chesed", as in this week's parsha in Breishit 24:49 where Eliezer asks that Rivka's family perform "Chesed V'Emet". I encourage you to view Ibn Ezra's commentary, there. Essentially, he says that "Chessed" is something that is not required and "Emet" is something done to establish the "chesed". The point is, that Eleizer prefaces this with the word "osim" - to DO, meaning a physical, realistic act. Thus this lends support to the notion that "Emet" is based on physical reality and not just plain "vacuous" concepts of "truth" referring to things that don't exist.
It appears that Judaism does accept such a logical construct in halacha. Heter iska is an example of such a construct.
If I am a chicken then this money I pay you is profit and not interest
This is a true statement in the empty sense and is accepted as valid by Jewish law. Why such a statement is acceptable is the subject of a separate question.
