NETM = | M is a TM and L(M)=â∅. What is the meaning of NETM?
1) NETM is the set of all Turing Machines
2) NETM is the set of all Turing Machines whose language is not empty
3) NETM is the set of all Turing Machines whose language is empty
4) NETM is the set of all Turing Machines that accept at least one string