> I became rather jaded on the Liskov substitution principle after reading https://okmij.org/ftp/Computation/Subtyping

The root of the issue here is that Liskov substitution principle simply references ϕ(x) to be some property satisfied by objects of a class. It does not distinguish between properties that are designed by the author of the class to be satisfied or properties that happen to be satisfied in this particular implementation. But the Hyrum’s Law also states that properties that are accidentally true can become relied upon and as time passes become an intrinsic property. This to me suggests that the crux of the problem is that people don’t communicate sufficiently about invariants and non-invariants of their code.