Comment by grumblenum

Types that can be defined by users are, necessarily, part of a language syntax, so that they are aligned with the syntax is just a tautology. Equating user defined types with formal verification is just nonsense. C has types. Python has types. Rust has types. That the program does what you think it should do does not logically follow the mere existence of types. I have no idea what "in the large" is supposed to mean. I feel like GPT-3 is arguing with me.