decidable P6. Let ={a,b,c}. Show that (a) E' is countable (6) The set of all languages over is uncountable P7. It is known that { G is CFG and L(G) = 2*) is undecidable. Show that language {: G1, G2 are CFG and L(G1)=L(G2)} is also undecidable. P8. Show that the language (: Mis T.M. and L(M) is nonempty) is recognizable