CMSI 3801: Quiz 2 Preparation

When

Last 10 minutes of class on Wednesday, September 23, 2026.

Everyone takes the exam at the same time.

Scope

Theories of computer science, Language Theory

Ground Rules

You will take the exam on paper. There is 10 minute time limit, or 15 minutes for those with time-and-a-half accommodations.

You may bring one sheet of paper with notes written on both sides.

Preparation Checklist

Do each of the following to maximize your preparation:

Review the recordings for class periods you missed, and for portions of the class sessions that you attended but feel you need to review.
Work through the course notes on Theories of Computer Science and Language Theory.
Watch the embedded videos in the course notes above.
Follow some of the links within the course notes to outside articles and videos. This gives you access to new material as well as additional takes on the course content.
Practice with the recall questions on the notes above.

Were you able to check off every box?

Things to Know

The learning objectives for the course up to this point in time include you having developed a familiarity with, and an ability to discuss:

The scope and big ideas of each of the four theories of computer science: languages, automata, computability, and complexity
Key definitions and concepts in language theory
The ability to craft grammars for formal languages
The ability to generate derivations and derivation trees for formal languages
An understanding of ambiguity in grammars

Outline of Course Content

The fact that active recall is better for acquiring long-term knowledge does not mean that outlines and concept maps are not useful. Learners should use multiple techniques—think “both and” rather than “either or.”

Theories of Computation, The Basics
    What is a theory?
        Organized body of knowledge with explanatory and predictive power
    Why study theory?
        To have a vocabulary for communication
        To reason from more fundamental and precise principles
        To predict and generate new knowledge
        To not flail and guess and have our thinking stuck in a box
    Big questions in computer science
        What is computation?
        What can and cannot be known through computation?
        What can and cannot be computed?
        What can and cannot be efficiently computed?
    Language Theory
        Definition: how computations are expressed
        Symbols
        Alphabets
        Strings
        Languages
        Functions
    Automata Theory
        Definition: how computations are carried out
        Early computing machines
        How and why Turing came up with his machine model
        Representing a Turing Machine as a table
        Representing a Turing Machine as a state diagram
    Computability Theory
        Definition: what computations are (theoretically)possible
        Why not every function is computable
            The simple counting argument: there are more functions than programs
        Church-Turing Thesis
        The Halting Problem
    Complexity Theory
        Definition: what resources are required for computations
        Kinds of computability measures
        P vs. NP
Language Theory
    Symbols
    Alphabets
    Strings
        Length, reversal, concatenation, substring
    Formal Languages
        Operations: union, intersection, complement, concatenation, Kleene star
    Syntax
        Generation vs. Recognition
    Generative Grammars
        Variables and rules
        Notation
        Lots of examples
        Predefined variables
        Derivations and Derivation Trees
        Ambiguity
        Formal Definition
        Not every language is describable by a generative grammar
        Restrictions
            Type 1 (context sensitive, noncontracting)
            Type 2 (context-free)
            Type 3 (regular)
            Chomsky Hierarchy
            Linear
        Regular expressions
    Analytic Grammars
    Semantics
    PLT
    Applications of Language Theory

About the Problems

This is a timed mini-quiz which tests for immediate understanding of topics and not your ability to work out problems over an extended duration of time. There will be 8 questions. Some may be multiple choice, multi-select, matching, and very short answer.

All content on the assigned readings is fair game for questions, so do not neglect the readings, and by all means do the recall questions!