Introduction to Logic CS157 Autumn 2025 Lectures TTh 13:30 - 14:50 Gates B1

Welcome

CS 157 is a rigorous introduction to Symbolic Logic from a computational perspective. It focusses on the encoding of information in the form of logical sentences; it covers various methods for reasoning with information represented in this form; and it provides an overview of logic technology and its applications (in mathematics, science, engineering, business, law, and so forth). Topics include the syntax and semantics of Propositional Logic, Relational Logic, and Term Logic, validity, contingency, unsatisfiability, logical equivalence, entailment, consistency, direct deduction (Hilbert), natural deduction (Fitch), refutation reasoning (Resolution), mathematical induction, reasoning with equality, compactness, soundness, completeness.

The course is divided into three main sections - Propositional Logic, Relational Logic, Term Logic (Logic with function symbols). See the table below for a tentative schedule of lessons, quizzes, and reviews.

This year, the lectures will take place in Gates B1 on Tuesdays and Thursdays from 1:30 to 2:50. There will be in-person office hours with the teaching staff. Times and locations will be posted on this page when they are finalized.

All of the materials for the course are online. Click on the "Lessons" tab at the top of this page to access these materials. There are links to textbook chapters, lecture slides, interactive exercises, puzzles, and sundry other items. Note that, as you proceed through the online materials, you may occasionally encounter technical problems. Apologies in advance if this happens to you. We are constantly working on the course. You may get extra credit for reporting such problems (especially if your reports are more constructive than irate).

Collaboration with your fellow students is acceptable and strongly encouraged. Feel free to discuss the subject matter and the problems either directly or using Ed Discussion. Our experience has shown that it is useful for students to work together to understand the material of the course and to solve problems. That said, you are expected to do quizzes in this course on your own; and you are responsible for understanding and being able to explain your answers.

Your grade for the course will be based on your scores on three online quizzes - one on Propositional Logic, one on Relational Logic, and one on Term Logic. The first quiz will count for 40% of your grade; the second will count for 30%; and the third quiz will count for 30%. We will also award a few points of extra credit based on discretionary factors, such as class attendance, participation in the Forum, and work on the puzzles. As preparation for the quizzes, we highly recommend that you review the online exercises, as the problems on the quizzes will closely resemble these exercises. In the past, we have offered an optional final for those who wish to make up for weak performance on the quizzes. We will almost certainly do the same this year.