undecidability

Which of the following is/are undecidable?

Consider the following two statements about regular languages: S 1 : Every infinite regular language contains an undecidable language as a subset. S 2 : Every finite language is re...

Which of the following languages are undecidable? Note that $$\langle M\rangle $$ indicates encoding of the Turing machine M. L 1 = $$\left\{ {\langle M\rangle |L\left( M \right) =...

Consider the following problems. $$L(G)$$ denotes the language generated by a grammar $$G.$$ $$L(M)$$ denotes the language accepted by a machine $$M.$$ $$\,\,\,\,\,\,\,\,{\rm I}.\,...

Which of the following decision problems are undecidable? $$\,\,\,\,\,\,\,\,\,\,{\rm I}.\,\,\,\,\,\,\,\,\,\,$$ Given $$NFAs$$ $${N_1}$$ and $${N_2},$$ is $$L\left( {{N_1}} \right)...

Which one of the following problems is un-decidable?

Which of the following is/are undecidable? $$1.$$ $$G$$ is a $$CFG.$$ Is $$L\left( G \right) = \Phi ?$$ $$2.$$ $$G$$ is a $$CFG.$$ Is $$L\left( G \right) = \sum {{}^ * } ?$$ $$3.$$...

Consider three decision problems $${P_1},$$ $${P_2}$$ and $${P_3}.$$ It is known that $${P_1}$$ is decidable and $${P_2}$$ is un-decidable. Which of the following is TRUE?

State whether the following statement is TRUE / FALSE. The problem is to whether a Turing Machine M accepts input $$w$$ is un-decidable.