These techniques can be "sound", meaning that the verified properties can be logically deduced from the semantics, or "unsound", meaning that there is no such guarantee. A sound technique yields a result only once it has searched the entire space of possibilities. An example of an unsound technique is one that searches only a subset of the possibilities, for instance only integers up to a certain number, and give a "good-enough" result. Techniques can also be "decidable", meaning that their algorithmic implementations are guaranteed to terminate with an answer, or undecidable, meaning that they may never terminate. Because they are bounded, unsound techniques are often more likely to be decidable than sound ones.