Sure, I don't think anyone is realistically expecting to verify all existing legacy spaghetti code -- _that's_ an interesting research direction, at best.
The point upthread (at least the point I took) is not that existing code doesn't do things to make it difficult to verify, but rather there's no reason inherent to the desired behavior of those programs that it _needs_ to be difficult to verify them. Nor is there good reason going forward to not lean towards tools that make verification more tractable for anything new we write.
The point upthread (at least the point I took) is not that existing code doesn't do things to make it difficult to verify, but rather there's no reason inherent to the desired behavior of those programs that it _needs_ to be difficult to verify them. Nor is there good reason going forward to not lean towards tools that make verification more tractable for anything new we write.