Intersection of decidable and undecidable language. Equivalence Problem Since we no...

Intersection of decidable and undecidable language. Equivalence Problem Since we now know that the class of context-free languages is not closed under either intersection or com-plement, it seems hopeless to believe that the equivalence problem for context-free languages is decidable. Can an intersection of two context-free languages be an undecidable language? Ask Question Asked 11 years, 8 months ago Modified 11 years, 8 months ago A recursive language is a formal language for which there exists a Turing machine that decides it. Jul 11, 2025 · Prerequisite - Undecidability, Decidable and undecidable problems Identifying languages (or problems*) as decidable, undecidable or partially decidable is a very common question in GATE. Depending on how they can be solved, languages are divided into the following types: Decidable Languages Partially Decidable Languages Undecidable Languages Decidable Language A Decision problems: decidable and undecidable We want to show that certain problems can not be solved by a computer. But this intersection is exactly L, the language shown to be unrecognizable, and thus surely undecidable, in the previous proof. Theorem 12. One could encode the answers to an undecidable problem (like a version of the Halting Problem) into the advice string A = (a 0, a 1, a 2, ) A = (a0,a1,a2,…). Exam style online tests with answers based on the latest 2026-27 exam pattern. 2 & 5. Can we use this to find other non-RE languages? Decidability and Class R How do we formalize the idea of an algorithm? Undecidable Problems What problems admit no algorithmic solution? The empty language is clearly decidable (just take the Turing machine that always returns false). dnqu ihtbkym wmczitq dccmhc fspo cfkz jkgo gunev oykt ptl