ECS 120 – Fall 2019 – Phillip Rogaway

Details get filled in as the course progresses.
This term has 28 class meetings (two were stolen without your consent)
The schedule from Spring 2015 serves as an example for where we will head.

ECS 120 – Theory of Computation – Spring 2023 – Phillip Rogaway

Lecture Topic

1M 4/03 Inroduction to our class. Three sample problems and their relative complexities.

1W 4/05 Language-theoretic basics: alphabets and strings. In CS, everything is a string. Operators on strings.

1F 4/07 Q1: first quiz. Languages. Operations on languages, like concatenation.

2M 4/10 More opns on languages: union, intersection, complement. Star. Reguarlar langauges, expressions.

2W 4/12 Defining the language of a regular expression. Examples of DFAs.

2F 4/14 Q2. More pracice with reg expressions and DFAs. Defn of a DFA. The language of a DFA.

3M 4/17 Reviewing defns. Closure properties of the DFA-acceptable languages, including the product construction.

3W 4/19 Give blood? NFAs: examples and closure properties.

3F 4/21 Q3 due (available noon 4/20 to noon 4/21). Formalizatoin of NFAs. The subset construction.

4M 4/24 Going over Q3. The regular languages are the NFA/DFA-acceptable languages.

4W 4/26 Showing a DFA minimal. Showing a language not regular. A pumping lemma for regular languages.

4F 4/28 Q4. Students leave. Go over Q4. Examples of using the pumping lemma. Stronger forms of it.

5M 5/01 (a) Pumping lemma. Other ways to show L not regular. (b) Decision procedures. (c) Karim; rest in peace.

5W 5/03 No dogs came. More decision procedures. Grammars. Regular langs = langs of right-linear grammars.

5F 5/05 Q5 due. Linear, context-free, unrestricted grammars. NPDAs. A not-CF language. Parse trees. Ambiguity.

6M 5/08 Almost-dog-day. Review of grammars. Turning machine, informal and formal.

6W 5/10 An example TM. Formally defining TMs and how they compute.

6F 5/12 Q6. Review of TMs. Definition of decidable (recursive) and acceptable (r.e.) languages.

7M 5/15 Student art. Review of rec/r.e.. TM variants. Church-Turing/digital-modelling theses. A children’s book

7W 5/17 Arguments for and against the Church-Turing thesis. Undecidability of Atm.

7F 5/19 Q7. Review Atm. 4-possiblities thm. Countably many r.e. langauges; uncountably many langauges.

8M 5/22 Music for elephants. Classification guesses. Computable functions. Many-one rdxns. Their properties.

8W 5/24 Reviewed many-one rdxn and their use. Then we did examples of reductions: BTHP, FINITE.

8F 5/26 Q8. More reductions. Problems DIOPHANTINE and PCP. Undecidability is ubiquitous.

9M 5/29 Memorial Day. No class. Go play.

9W 5/31 The class P and what it captures. The class NP. Examples: DFAEQ, NFAEQ, GSAT.

9F 6/02 Q9. Reviewing P and NP. Def of a poly-time reduction. NP-Completeness. Cook-Levin Thm

10M 6/05 Practice doing NP-Completeness reductions. GSAT, 3SAT, and G3C. Gadgets.

10T 6/06 6-8pm: Review session in Roessler 66. Do the 2014 practice-final first.

10W 6/07 Awards! Interactive Proofs (IP) and zero-knowledge (ZK). IP = PSPACE. G3C (and all of NP) in ZK.

10F 6/09 10:30 am: Final exam. The room is:
Roessler 66 if your SID ends 0|2|4|6|8
Giedt 1003 if your SID ends 1|3|5|7|9

ECS 120 – Theory of Computation – Spring 2023 – Phillip Rogaway
Lecture	Topic
1M 4/03	Inroduction to our class. Three sample problems and their relative complexities.
1W 4/05	Language-theoretic basics: alphabets and strings. In CS, everything is a string. Operators on strings.
1F 4/07	Q1: first quiz. Languages. Operations on languages, like concatenation.
2M 4/10	More opns on languages: union, intersection, complement. Star. Reguarlar langauges, expressions.
2W 4/12	Defining the language of a regular expression. Examples of DFAs.
2F 4/14	Q2. More pracice with reg expressions and DFAs. Defn of a DFA. The language of a DFA.
3M 4/17	Reviewing defns. Closure properties of the DFA-acceptable languages, including the product construction.
3W 4/19	Give blood? NFAs: examples and closure properties.
3F 4/21	Q3 due (available noon 4/20 to noon 4/21). Formalizatoin of NFAs. The subset construction.
4M 4/24	Going over Q3. The regular languages are the NFA/DFA-acceptable languages.
4W 4/26	Showing a DFA minimal. Showing a language not regular. A pumping lemma for regular languages.
4F 4/28	Q4. Students leave. Go over Q4. Examples of using the pumping lemma. Stronger forms of it.
5M 5/01	(a) Pumping lemma. Other ways to show L not regular. (b) Decision procedures. (c) Karim; rest in peace.
5W 5/03	No dogs came. More decision procedures. Grammars. Regular langs = langs of right-linear grammars.
5F 5/05	Q5 due. Linear, context-free, unrestricted grammars. NPDAs. A not-CF language. Parse trees. Ambiguity.
6M 5/08	Almost-dog-day. Review of grammars. Turning machine, informal and formal.
6W 5/10	An example TM. Formally defining TMs and how they compute.
6F 5/12	Q6. Review of TMs. Definition of decidable (recursive) and acceptable (r.e.) languages.
7M 5/15	Student art. Review of rec/r.e.. TM variants. Church-Turing/digital-modelling theses. A children’s book
7W 5/17	Arguments for and against the Church-Turing thesis. Undecidability of Atm.
7F 5/19	Q7. Review Atm. 4-possiblities thm. Countably many r.e. langauges; uncountably many langauges.
8M 5/22	Music for elephants. Classification guesses. Computable functions. Many-one rdxns. Their properties.
8W 5/24	Reviewed many-one rdxn and their use. Then we did examples of reductions: BTHP, FINITE.
8F 5/26	Q8. More reductions. Problems DIOPHANTINE and PCP. Undecidability is ubiquitous.
9M 5/29	Memorial Day. No class. Go play.
9W 5/31	The class P and what it captures. The class NP. Examples: DFAEQ, NFAEQ, GSAT.
9F 6/02	Q9. Reviewing P and NP. Def of a poly-time reduction. NP-Completeness. Cook-Levin Thm
10M 6/05	Practice doing NP-Completeness reductions. GSAT, 3SAT, and G3C. Gadgets.
10T 6/06	6-8pm: Review session in Roessler 66. Do the 2014 practice-final first.
10W 6/07	Awards! Interactive Proofs (IP) and zero-knowledge (ZK). IP = PSPACE. G3C (and all of NP) in ZK.
10F 6/09	10:30 am: Final exam. The room is: Roessler 66 if your SID ends 0\|2\|4\|6\|8 Giedt 1003 if your SID ends 1\|3\|5\|7\|9