GEB: Hofstadter

6 flashcards · Mathematics · by lakesare

1. What does Hofstadter mean by the well-formed formula (WFF) VS the theorem?

   Well-formed formula - a string from the RHS given any LHS. Can be yielded by any of the rules given some lhs, whether or not that lhs can be derived from the axioms of the languageTheorem - a string that can certainly be derived. A word in a language.

2. Consistency VS completeness?

   consistency - when every theorem, upon interpretation, comes out true Everything produced by the system is true.completeness - when all statements which are true and can be expressed as well-formed strings, are theorems Every true statement is produced by the system.

3. What's special about Rosetta Stone? Patrons at the British Museum view the Rosetta Stone as it was displayed in 1985.The ancient Greek on the Rosetta Stone told archaeologists that it was inscribed by priests honoring the king of Egypt, Ptolemy V, in the second century B.C.

   It contained the same message written in: in Ancient Egyptian (hieroglyphic script) in Ancient Egyptian (demotic script) in Ancient Greek. This allowed scientists to decipher the Egyptian text. More startlingly, the Greek passage announced that the three scripts were all of identical meaning. The artifact thus held the key to solving the riddle of hieroglyphics, a written language that had been "dead" for nearly 2,000 years.Hieroglyphics used pictures to represent objects, sounds and groups of…

4. What's this?

   A jukebox. A coin-operated phonograph or compact-disc player that automatically plays recordings selected from its list.

5. What's the difference between: primitive recursive functions VS general recursive functions?

   primitive recursive functions - for loop allowed general recursive functions - while loop allowed

6. Name 2 types of recursive functions.

   primitive recursive functions for loop allowedgeneral recursive functions while loop allowed