As in there's an objective truth that can be determined by a computer. E.g. whether code compiles, whether a unit test passes, whether the answer given to a mathematical question like 3+5 is correct. Many other fields have no objective truth (like art or creative writing), or objective truth requires measurement of the physical world (although if the world can be simulated accurately enough for the problem class at hand, then sufficient training data can still be generated by a computer).