Halting problem of Turing machines is undecidable

Determining whether a context-free grammar is ambiguous is undecidable

Given two arbitrary context-free grammars G1 G2 and it is undecidable whetherL (G1) = L (G2).

Given two regular grammars G1G2 and it is undecidable whether L (G1) = L (G2)

proving whether a promotive recursive function is turning computable or not

proving whether a primitive recursive function is a total function or not

generating primitive recursive functions

generating partial recursive functions

recursive

recursively enumerable

NP-HARD

none of these

L = {an bn an| n = 1, 2, 3...} is recursively enumerable

Recursive languages are closed under union

Every recursive is closed under union

All of these

stored program computers

interpretative implementation of program­ming language

computability

all of these