Select all true statements, for all A, B1 pointIf A and B are decidable, then A union B is decidable.If A and B are decidable, then A intersection B is decidable.If A union B is decidable, then A is decidable and B is decidable.If A intersection B is decidable, then A is decidable and B is decidable.If A union B is decidable, then A is decidable or B is decidable.If A intersection B is decidable, then A is decidable or B is decidable.

Let A be some decidable language and let B be some undecidable language. Select all statements that are definitely false no matter what A and B are.1 pointA ≤ AA ≤ BB ≤ AB ≤ BB ≤ HALTSHALTS ≤ B

Select all true statements1 pointThere is a TM that loops on all inputsLet A be any decidable language. There is a TM that loops on exactly the strings not in A.Let A be any decidable language. There is a TM that loops on exactly the strings in A.There is an undecidable language A such that there is a TM that halts on exactly the strings in A.There is an undecidable language A such that the complement of A is decidable.There is a decidable language A such that the complement of A is undecidable.

A is some decidable language. Select all statements that are true irrespective of what A is.1 pointHALTS ≤ HALTS'HALTS' ≤ HALTSA ≤ HALTS'HALTS' ≤ A

Select all statements equivalent to "Language A is decidable by a TM."1 pointA is decidable by a C programA is decidable by a Python programA is decidable by a NFAA is decidable by a PDAA is decidable by a context-free grammar

Suppose A ≤ B and B ≤ C and C is undecidable, then:1 pointA is decidableA is undecidableB is decidableB is undecidableA could be decidable or undecidable, it depends on what A, B, C are.B could be decidable or undecidable, it depends on what A, B, C are.