Math 29 Homework #20

I will not go so far as to say that to construct a history of thought
without profound study of the mathematical ideas of successive epochs
is like omitting Hamlet from the play which is named after him.
That would be claiming too much.
But it is certainly analogous to cutting out the part of Ophelia.
This simile is singularly exact. For Ophelia is quite essential to the play,
she is charming - and a little mad.
Alfred North Whitehead

Reading

Read what we covered in today's class: 6.6
Read what we will cover in the next class: 7.1, 7.2

When reading 6.6 pay special attention to the following concepts:

  • the definition of partially decidable, the examples in 6.2, the characterization of partially decidable predicates in Theorems 6.3 & 6.4, the closure of partially decidable predicates under existential quantification given by Theorem 6.5, diophantine predicates, the equivalence of diophantine and partially decidable predicates given by Theorems 6.9 & 6.10
When reading 7.1 pay special attention to the following concepts:
  • characteristic function, recursive/computable sets, the examples of computable sets, and Theorem 1.3 which lists some nice properties of computable sets
When reading 7.2 pay special attention to the following concepts:
  • The definition and basic examples of c.e. sets, Theorems 2.3,4,5,6 which utilize what we already know about partially decidable predicates to provide information about c.e. sets, the characterization of c.e. sets given by Theorem 2.7, the characterization of the set of indices of total computable functions given by Theorem 2.9 (you should find this particularly interesting), the connection between c.e. sets and diophantine predicates, and the algebraic facts about c.e. sets given by Theorem 2.13.

Problems

The following problems are due by the beginning of class on Friday 5/14.
  • Define and give examples of the following:
    • recursive set
    • recursively enumerable set
    • diophantine set
  • p. 119, # 6.6.14.6
  • p. 119, # 6.6.14.8
  • p. 119, # 6.6.14.9
  • p. 122, # 7.1.4.1a

Presentations

  • Joran, Theorem 7.2.16 on Monday 5/17
  • David, Theorem 7.3.2 and 7.3.4 on Wednesday 5/19
  • Amanda, Theorem 7.4.2 and 7.4.3 on Monday 5/24