Problem: Static analysis techniques for software verification can be applied also in the scenario of query languages. In particular, the *Abstract interpretation framework has been extended to the field of query languages for relational databases as a way to support sound approximation techniques. The semantics of query languages can be tuned according to suitable abstractions of the concrete domain of data. The abstraction of relational database system has many interesting applications, in particular, for security purposes, such as fine grained access control, watermarking, etc.
What is a security measure that no longer uses a relational database system?
---
Answer: unanswerable


Problem: Many minerals provide pigments which have been used in green paints and dyes over the centuries. Pigments, in this case, are minerals which reflect the color green, rather that emitting it through luminescent or phosphorescent qualities. The large number of green pigments makes it impossible to mention them all. Among the more notable green minerals, however is the emerald, which is colored green by trace amounts of chromium and sometimes vanadium. Chromium(III) oxide (Cr2O3), is called chrome green, also called viridian or institutional green when used as a pigment. For many years, the source of amazonite's color was a mystery. Widely thought to have been due to copper because copper compounds often have blue and green colors, the blue-green color is likely to be derived from small quantities of lead and water in the feldspar. Copper is the source of the green color in malachite pigments, chemically known as basic copper(II) carbonate.
What do pigments do with the color green?
---
Answer: reflect


Problem: Publius Vergilius Maro (Classical Latin: [ˈpuː.blɪ.ʊs wɛrˈɡɪ.lɪ.ʊs ˈma.roː]; October 15, 70 BC – September 21, 19 BC), usually called Virgil or Vergil /ˈvɜːrdʒᵻl/ in English, was an ancient Roman poet of the Augustan period. He is known for three major works of Latin literature, the Eclogues (or Bucolics), the Georgics, and the epic Aeneid. A number of minor poems, collected in the Appendix Vergiliana, are sometimes attributed to him.
What is Virgil's longest book?
---
Answer:
unanswerable