The meaning of "proof" in a computer science context is much stronger than that. A proof does involve demonstration, but it's demonstration via a deductive logi

The meaning of "proof" in a computer science context is much stronger than that. A proof does involve demonstration, but it's demonstration via a deductive logical argument that shows that the conclusion is logically guaranteed to follow from the premises. Compiler error messages would be a lot more verbose if they did that rigorously.