I guess you get a combinatorial explosion for binary operators: https://en.wikipedia.org/wiki/Three-valued_logic https://en.wikipedia.org/wiki/Three-valued_logi

I guess you get a combinatorial explosion for binary operators: https://en.wikipedia.org/wiki/Three-valued_logic https://en.wikipedia.org/wiki/Three-valued_logic That's not to say that you can't get some value out of it. SQL is probably the closest language currently to implement TVL, and there have been recent works on datalog as well: https://arxiv.org/pdf/2202.01718.pdf https://arxiv.org/pdf/2202.01718.pdf Datalog has generally better defined reasoning than SQL, and can kinda serve duty for typechecking, formal verification. It's worth noting that many languages have the (disjointed) concept of uninitialised values which are equivalent to TVL (Also note nullable types in eg. C#). As such, from a practical perspective, TVL is pushed out as much as possible from code, I suspect it's of more use for data.