III. return the bill to Congress for clarification on some point within the bill IV. allow the Congress to pocket veto the bill, thereby allowing the bill to become law without his signature a.
Decidability. Definition: A language is called decidable if there exists a method-any method at all-to determine whether a given word belongs to that language or not. Working hypothesis I: Decidability is well defined above.roof: Surely, a decidable language is recognizable. Moreover, if a language is decidable, then so is its complement, and hence that complement is recognizable. Now suppose a language L and its complement are recognizable. Let A be a recognizer for L, and B for its complement.
Recursive set. In computability theory, a set of natural numbers is called recursive, computable or decidable if there is an algorithm which terminates after a finite amount of time (which may depend on the given number) and correctly decides whether a given number belongs to the set.