CSU 290 Spring 2009 Announcements
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html
CSU 290 Spring 2009 AnnouncementsOffice hours tomorrowSun, 19 Apr 2009 00:08:00 ESTRiccardo Pucella
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html/Sun--19-Apr-2009-Office-hours-tomorrow
I've moved my office hours tomorrow to 13h00-15h00, as I have a
conference call at 15h00 that I need to take.
Preparing grade reportsThu, 16 Apr 2009 00:08:00 ESTRiccardo Pucella
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html/Thu--16-Apr-2009-Preparing-grade-reports
I've gotten the final grades for homework 6, and I'm finishing to
correct that little grading errors that have made their ways into
blackboard. I will be
tabulating the grades and sending you all a report later tonight. So
check your email, and you'll be able to determine whether you need to
take the final or not. (You can probably figure it out already, but
this may save you some time.)
Last bits of lectures notesWed, 15 Apr 2009 00:08:00 ESTRiccardo Pucella
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html/Wed--15-Apr-2009-Last-bits-of-lectures-notes
First off, added an addendum to the <a href="http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/lect29-fol.pdf">first-order
logic lecture notes</a> giving two informal proofs of the theorems we
proved in gory details. And I added the lecture notes
for <a href="http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/lect30-inductive.pdf">informal
proofs by induction</a>, the last lecture of the course.
Final examFri, 10 Apr 2009 00:08:00 ESTRiccardo Pucella
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html/Fri--10-Apr-2009-Final-exam
Final exam information from the Registrar's Office: <tt>04/23/2009
1:00 PM CS U290 LOGIC COMP 50 DG R.PUCELLA</tt>. So Thursday,
April 23, 13h00. DG 50 is Dodge Hall 50, I believe.
Lectures notes on first-order logicWed, 08 Apr 2009 00:08:00 ESTRiccardo Pucella
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html/Wed--08-Apr-2009-Lectures-notes-on-first-order-logic
Lecture notes for this afternoon's lecture
on <a href="http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/lect29-fol.pdf">first-order
logic</a> are up. I also uploaded a PDF version of Monday's phantom
lecture on
<a href="http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/lect28-bst.pdf">binary
search trees</a>.
Solutions to homework 6Wed, 08 Apr 2009 00:08:00 ESTRiccardo Pucella
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html/Wed--08-Apr-2009-Solutions-to-homework-6
Sample <a href="http://www.ccs.neu.edu/course/csu290/unix-sols.lisp">solutions
for homework 6</a> are available. Note that there are many ways to
formalize some of the statements.
Lecture notes for missed lecture on MondayTue, 07 Apr 2009 00:08:00 ESTRiccardo Pucella
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html/Tue--07-Apr-2009-Lecture-notes-for-missed-lecture-on-Monday
I want to apologize again for the last minute cancel of Monday's
lecture. I would have talked about binary search trees. There's a
couple of other things I want to talk about tomorrow and next Monday,
so I won't actually cover that material, but I just made available to
<a href="http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/lect28-bst.lisp">executable
lecture notes</a> for the lecture, that you can run interactively in
ACL2s. For your edification, if you will, and they provide an
example of a nontrivial ADT specification.
Updates on lectures notesTue, 07 Apr 2009 00:08:00 ESTRiccardo Pucella
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html/Tue--07-Apr-2009-Updates-on-lectures-notes
After a chat with Richard Zelinsky, I've decided to slightly modify
the lecture notes on observational equivalence (and the corresponding
bit in the lecture on binary trees), to make clear the notion of an
invariant. Really what we define is an equivalence between
representations, and we prove that that equivalence is an invariant of
th eoperations. Hopefully, things are a bit clearer now.
Lecture on binary treesFri, 03 Apr 2009 00:08:00 ESTRiccardo Pucella
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html/Fri--03-Apr-2009-Lecture-on-binary-trees
Last update of the day, promised. Posted lecture notes on
<a href="http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/lect27-binary-trees.pdf">binary
trees</a>. We're now up-to-date with respect to lecture
notes. Monday, binary search trees.
Code for homework 6Fri, 03 Apr 2009 00:08:00 ESTRiccardo Pucella
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html/Fri--03-Apr-2009-Code-for-homework-6
In case you did not notice, we have added the code <tt>unix.list</tt>
for homework 6 in the
<a href="http://www.ccs.neu.edu/course/csu290/assignments.html">assignments</a>
page.
Lectures 24 and 25Fri, 03 Apr 2009 00:08:00 ESTRiccardo Pucella
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html/Fri--03-Apr-2009-Lectures-24-and-25
The lecture notes
on <a href="http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/lect24-specifications.pdf">interfaces
and specifications</a> and
on <a href="http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/lect25-adts.pdf">ADTs</a>
have been posted. I'll post the remaining notes (on binary trees)
later tonight.
Homework 6 and next midtermFri, 03 Apr 2009 00:08:00 ESTRiccardo Pucella
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html/Fri--03-Apr-2009-Homework-6-and-next-midterm
Homework 6 is available from the
<a href="http://www.ccs.neu.edu/course/csu290/assignments.html">assignments</a>
page, due at midnight, Tue April 7. Also, <strong>midterm 6,
originally scheduled for Wed April 8, has been moved to Thu April
9</strong>.
Lecture 26 is upThu, 02 Apr 2009 00:08:00 ESTRiccardo Pucella
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html/Thu--02-Apr-2009-Lecture-26-is-up
Posted <a href="http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/lect26-obs-equivalence.pdf">lecture
notes on observational equivalence</a> are up. Lectures 24 & 25 will
go up tomorrow morning - they're on my office computer.
Solutions to homework 5 and midterm 5 reminderTue, 24 Mar 2009 00:08:00 ESTRiccardo Pucella
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html/Tue--24-Mar-2009-Solutions-to-homework-5-and-midterm-5-reminder
Solutions to
homework 5 <a href="http://www.ccs.neu.edu/course/csu290/assignments.html">are
available</a>, again using the "alternative" proof
notation that I described at the end of the lecture 14. And, of
course, a reminder that tomorrow (Wednesday) is the fifth midterm,
covering generalization, proving in ACL2, and rewriting.
Lectures note on rewritingMon, 23 Mar 2009 00:08:00 ESTRiccardo Pucella
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html/Mon--23-Mar-2009-Lectures-note-on-rewriting
Posted <a href="http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/lect23-rewriting.pdf">lecture
notes on rewriting</a>. Today's lecture ended up being a review of
generalization, and looking at problems 1(b), 2(c), and 4 on the last
homework.
Reminder: homework 5Thu, 19 Mar 2009 00:08:00 ESTRiccardo Pucella
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html/Thu--19-Mar-2009-Reminder:-homework-5
I just wanted to remind you that homework 5 is available from the
<a href="http://www.ccs.neu.edu/course/csu290/assignments.html">assignments</a>
page, and that you <i>only have to do the first 5 questions</i>. You
do not have to do question 6, although feel free to try, you should
know everything needed to complete it anyways.
Lectures notes on ACL2Thu, 19 Mar 2009 00:08:00 ESTRiccardo Pucella
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html/Thu--19-Mar-2009-Lectures-notes-on-ACL2
Posted lecture notes for
the <a href="http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/lect21-acl2.pdf">two</a>
<a href="http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/lect22-acl2.pdf">lectures</a>
on ACL2 earlier this week. Lecture notes on rewriting coming up soon.
Lecture notes on generalizationThu, 12 Mar 2009 00:08:00 ESTRiccardo Pucella
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html/Thu--12-Mar-2009-Lecture-notes-on-generalization
<a href="http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/lect20-generalization.pdf">Lectures
notes for today's lecture</a> on generalization are up.
Lecture notes and solutions to homework 4Mon, 09 Mar 2009 00:08:00 ESTRiccardo Pucella
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html/Mon--09-Mar-2009-Lecture-notes-and-solutions-to-homework-4
<a href="http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/lect19-reverse.pdf">Lectures
notes for today's lecture</a> on the review using <tt>rev</tt> are
up. There's a bit at the beginning and a bit at the end that I never
got to but is useful, so please read it. Also, solutions to
homework 4 have been posted on the <a href="http://www.ccs.neu.edu/course/csu290/assignments.html">homeworks page of the main web
site</a>. Again, the solutions use the "alternative" proof notation
that I described at the end of the lecture 14.
Lecture notes on induction (part II)Thu, 26 Feb 2009 00:08:00 ESTRiccardo Pucella
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html/Thu--26-Feb-2009-Lecture-notes-on-induction-(part-II)
<a href="http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/lect18-nat-induction.pdf">Lecture
notes for today's lecture</a> on induction for other data types than
lists. Have a good and safe break, and see you all back in March.
Lecture notes on inductionWed, 25 Feb 2009 00:08:00 ESTRiccardo Pucella
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html/Wed--25-Feb-2009-Lecture-notes-on-induction
<a href="http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/lect17-induction.pdf">Lecture
notes for today's lecture</a> on induction are up. I did not
proofread carefully, so there may be typos. Let me know if you find any.
Think about proof obligations for the following formulaWed, 25 Feb 2009 00:08:00 ESTRiccardo Pucella
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html/Wed--25-Feb-2009-Think-about-proof-obligations-for-the-following-formula
Here is the formula that I wanted you to think about at the end of
class today, the one I blanked on. Try to come up with the proof
obligations for the following formula: <tt>(true-listp x) => (= (app x
nil) x)</tt>. In particular, try to "massage" the formula corresponding
to the inductive step into a form you can actually prove. Then, prove
both proof obligations, since that's a good exercise.
Lecture notes for termination and the definitional principleMon, 23 Feb 2009 00:08:00 ESTRiccardo Pucella
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html/Mon--23-Feb-2009-Lecture-notes-for-termination-and-the-definitional-principle
<a href="http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/lect16-def-principle.pdf">Lecture
notes for today's lecture</a> on termination and the definitional
principle are up.
I added some proving exercises at the beginning of the lecture, two of
which I gave in class, two I did not. Do then, it's good practice,
and they're not difficult.
Homework 4 is outSat, 21 Feb 2009 00:08:00 ESTRiccardo Pucella
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html/Sat--21-Feb-2009-Homework-4-is-out
<a href="http://www.ccs.neu.edu/course/csu290/hwk4.pdf">Homework 4</a>
is out, due at the end of Spring Break, March 7th. (You can do the
first two questions now, for the rest, we will cover the material
early next week.)
Lecture notes for case analysisThu, 19 Feb 2009 00:08:00 ESTRiccardo Pucella
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html/Thu--19-Feb-2009-Lecture-notes-for-case-analysis
<a href="http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/lect15-case-analysis.pdf">Lecture
notes for today's lecture</a> on case analysis are up.
Midterm 3 postmortemWed, 18 Feb 2009 00:08:00 ESTRiccardo Pucella
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html/Wed--18-Feb-2009-Midterm-3-postmortem
Here are the <a href="http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/postmortem3.txt">solutions to the midterm questions</a>, in case you were
curious, along with a quick postmortem of how overall you all did, and
the main problems encountered. We'll talk about it some tomorrow.
Sigh; fixed link to solutionsTue, 17 Feb 2009 00:08:00 ESTRiccardo Pucella
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html/Tue--17-Feb-2009-Sigh;-fixed-link-to-solutions
Sorry, it appears I messed up the link to the solutions file, unless
you happened to click on the link from the announcements page. <a href="http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/solutions3.txt">It's
fixed now</a>.
Done - solutions to questions 6 and 7 addedTue, 17 Feb 2009 00:08:00 ESTRiccardo Pucella
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html/Tue--17-Feb-2009-Done---solutions-to-questions-6-and-7-added
I've added the solution to questions 6 and
7 <a href="http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/solutions3.txt">to the solution file</a>. Again, make sure you
understand what's going on.
Oops... questions 6 and 7 missingTue, 17 Feb 2009 00:08:00 ESTRiccardo Pucella
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html/Tue--17-Feb-2009-Oops...-questions-6-and-7-missing
Sorry, I forgot to finish the solutions, questions 6 and 7 have not
been "converted". Hey, it's probably a good exercise to do so, if you
have not done so already :). I'll try to plop them up by the end of
the afternoon.
Homework 3 solutionsTue, 17 Feb 2009 00:08:00 ESTRiccardo Pucella
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html/Tue--17-Feb-2009-Homework-3-solutions
First off, I was away for the weekend, and while I expected to have
email access, I turned out to be wrong. So if you have sent me email
over the weekend, I should get to it today. If you had a question
about the homework, I hope you thought of emailing the friendly TAs
(such as your lab TA, always a good start). Anyways, solutions to
homework 3 have been posted on the <a href="http://www.ccs.neu.edu/course/csu290/assignments.html">homeworks page of the main web
site</a>. Note that the solutions use the "alternative" proof notation
that I described at the end of the lecture notes for last
Thursday. (What, you didn't read them? Shame... shame...)
Anyways, <a href="http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/solutions3.txt">here are the solutions to homework 3
using the proof structure I gave in class.</a> Make sure you
understand what's going on.
Office hours, revisedMon, 16 Feb 2009 00:08:00 ESTRiccardo Pucella
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html/Mon--16-Feb-2009-Office-hours--revised
Sorry to appear fickle, but something came up and coming in will be
harder than expected. So I will not be in this afternoon. To
compensate, I will be holding office hours tomorrow (Tuesday),
14h00-17h00. I will be in my office, just drop by if you have
questions.
Office hours on MondaySun, 15 Feb 2009 00:08:00 ESTRiccardo Pucella
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html/Sun--15-Feb-2009-Office-hours-on-Monday
I will hold my office hours tomorrow as usual, 14h00-16h00, even
though it's Presidents Day. I know, I have no life...
Cleaned up notes for last two lecturesThu, 12 Feb 2009 00:08:00 ESTRiccardo Pucella
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html/Thu--12-Feb-2009-Cleaned-up-notes-for-last-two-lectures
Lecture notes for the lecture
on <a href="http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/lect13-defs.pdf">definitions
and proving equality formulas</a> and on
<a href="http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/lect14-cond-formulas.pdf">
proving conditional equality formulas</a> have been posted. They
reflect what I have talked about in class, especially the second
lecture. I have also added some remarks at the end of the second
lecture that you should read, especially if you have some time before
the lab tomorrow.
Solutions to homework 2Tue, 10 Feb 2009 00:08:00 ESTRiccardo Pucella
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html/Tue--10-Feb-2009-Solutions-to-homework-2
Oops, forgot to mention this: the solutions to homework 2 are
available on
the <a href="http://www.ccs.neu.edu/course/csu290/assignments.html">homeworks
page</a>, if you're curious.
Preliminary lecture notes for WednesdayTue, 10 Feb 2009 00:08:00 ESTRiccardo Pucella
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html/Tue--10-Feb-2009-Preliminary-lecture-notes-for-Wednesday
Here are
the lecture
notes for tomorrow's lecture, and also Thursday's really, since
it's a bit long. If you read it through, you can do the homework. (You
may need to disregard the page that reviews one way of doing proofs -
we're doing things differently this week; and you also want to convert
formulas in the homework from the ACL2 notation to the logical
notation we've been using in class - pretty straightforward. I'll
review all of this tomorrow.) Off to bed now.
Homework 3 is outTue, 10 Feb 2009 00:08:00 ESTRiccardo Pucella
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html/Tue--10-Feb-2009-Homework-3-is-out
Homework 3
is <a href="http://www.ccs.neu.edu/course/csu290/assignments.html">out</a>. Note
that you haven't seen the theory for it yet, that will be
tomorrow. Actually, I will try to write up the notes for tomorrow
today and post them tonight, so that if you want you can start on the
homework tomorrow after having read the notes prior to the
lecture. (Does that make sense?) Also, be aware that the syntax of the
logic used in the homework 3 slightly different from the one I used in
class. (One of the downsides of getting sick over the weekend is that
I couldn't interact with the homework production as much.) I will
probably give you all a version of the homework adapted to our
section. A director's cut, if you will (or Section-2 cut?). The
homework content will of course be the same - it's just the
presentation of the formulas will be slightly different, in a way that
will be obvious in retrospect.
Lecture notes on ACL2 logic, first partMon, 09 Feb 2009 00:08:00 ESTRiccardo Pucella
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html/Mon--09-Feb-2009-Lecture-notes-on-ACL2-logic--first-part
Today's lecture on the ACL2 logic (equalities and function symbols) is
<a href="http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/lect12-functions.pdf">available</a>. The
lecture was very
much <a href="http://www.phdcomics.com/comics/archive.php?comicid=820">drinking
from the fire hose</a>, for which I somewhat apologize. But hey,
it's done now, and the terms have been defined. Some things to note
about the notes, which I did not have time to say in class, or plain
forgot: (1) How do you determine the truth of a formula when it has an
ACL2 expression in it? Same as what we saw in the "Propositional
Logic in ACL2" lecture, any non-<tt>NIL</tt> value is
true, <tt>NIL</tt> is false. (2) I forgot <emph>the most important
point of equational proofs</emph>: if <emph>F</emph> has an
equational proof, then <emph>F</emph> is valid. That is why equational
proofs are interesting. (3) While every theorem is valid, it
is not true that every valid formulas has an equational proof. This
is essentially the content of Godel's incompleteness theorem. (4) I decided to make the Rule of
Modus Ponens an actual rule, and not a derived rule. It is actually
possible to remove it from the system, but not in the setup I
gave. Sorry for having thought otherwise. We'll add more rules as time
goes on, when they come in handy. Off to bed now, head's spinning.
Some lectures notes from Section 1Tue, 03 Feb 2009 00:08:00 ESTRiccardo Pucella
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html/Tue--03-Feb-2009-Some-lectures-notes-from-Section-1
Some lecture notes from the first section of the course, taught by
Prof. Manolios, have
been <a href="http://www.ccs.neu.edu/course/csu290/lectures.html">posted</a>. Feel
free to have a look. They are doing doing things a bit differently than we
are in the first section, but you may benefit from the different
exposition and the contrast.
Latest lecture notes, and the midtermMon, 02 Feb 2009 00:08:00 ESTRiccardo Pucella
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html/Mon--02-Feb-2009-Latest-lecture-notes--and-the-midterm
Lecture notes for today, on extending propositional logic to deal with
<a href="http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/lect11-equality.pdf">equality</a>. I
changed a little bit the presentation I made in class, for clarity,
and I think it is now more understandable. I never got to the last
proof, though. The lecture notes also give the quiz (which will
not be graded thanks to Anna's inspired coin-toss call), and I
recommend everyone takes a stab at it again if they did not get it the
first time. That's what the midterm will be like. The midterm will
cover propositional logic (validity, satisfiability, truth tables,
equational proofs). Basically what we did last week, up to and
including Thursday. Today's material
is therefore not on the midterm. In class, I also
handed out a sheet with a <a href="http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/bank.pdf">list of basic propositional validities</a> that
you can take as given in your proofs. And as I stated in class, for
this midterm, when asked for an equational proof, I will ask you to do
it somewhat pedantically: perform at most one substitution at each step,
and write down the substitution you are using. Like in the notes, that
should be your model.
We want to have as much data as possible when grading, and it's hard
to tell what you are thinking sometimes when we do not see the steps
you go through in details. We'll relax on this point after the
midterm.
Some lecture notes correctionsMon, 02 Feb 2009 00:08:00 ESTRiccardo Pucella
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html/Mon--02-Feb-2009-Some-lecture-notes-corrections
Corrected lecture notes for lecture 8 on propositional logic; I
stupidly messed up the de Morgan duals. It shoud be all better now.
Lecture notes for lists and cons structuresSat, 31 Jan 2009 00:08:00 ESTRiccardo Pucella
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html/Sat--31-Jan-2009-Lecture-notes-for-lists-and-cons-structures
The lecture
of lists
and cons structures, the last lecture on "programming ACL2", is
now <a href="http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/lect07-cons-struct.pdf">available</a>.
Just in case you think we're oversimplifyingSat, 31 Jan 2009 00:08:00 ESTRiccardo Pucella
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html/Sat--31-Jan-2009-Just-in-case-you-think-we're-oversimplifying
On the off-chance some of you believe that what we're doing in class
with our equational proofs is useless for non-class work, I was
sitting down to finish up a research paper this morning with a
colleague, and she made a statement that essentially amounted to the
validity of the following propositional logic formula: <tt>(x =>
~y) <=> (x => ~(x => y))</tt>, where I use <tt>=></tt> for
implication, <tt><=></tt> for equivalence, and <tt>~</tt> for
negation.
I wasn't completely convinced, so I hammered out an equational proof,
and presto, validity established. Try it out, it's not a hard one.
Lectures notes for first lecturesFri, 30 Jan 2009 00:08:00 ESTRiccardo Pucella
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html/Fri--30-Jan-2009-Lectures-notes-for-first-lectures
Slowly working my way up the stack - I've posted the <a href="http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/lect01-6-intro-acl2.pdf">lecture notes for
the first six lectures</a>. Only the lecture on deconstructing lists left,
and I'm up to date.
Lecture notes on propositional logic in ACL2Thu, 29 Jan 2009 00:08:00 ESTRiccardo Pucella
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html/Thu--29-Jan-2009-Lecture-notes-on-propositional-logic-in-ACL2
Lecture notes for today's lecture on propositional logic in ACL2 are
<a href="http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/lect10-prop-acl2.pdf">available</a>. I
haven't proofread them yet, so there may be typos, be warned.
Lecture notes on equational proofsWed, 28 Jan 2009 00:08:00 ESTRiccardo Pucella
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html/Wed--28-Jan-2009-Lecture-notes-on-equational-proofs
Lecture notes for today's lecture on equational proofs are
<a href="http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/lect09-eq-proof.pdf">available</a>. Please
do the exercise, it's good practice. I also very slightly modified the
lecture notes on propositional logic, restating the Principle
of Substitution to match the one gave in class.
Lecture notes on propositional logicTue, 27 Jan 2009 00:08:00 ESTRiccardo Pucella
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html/Tue--27-Jan-2009-Lecture-notes-on-propositional-logic
Lecture notes for yesterday on propositional logic
are <a href="http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/lect08-prop-logic.pdf">available</a>. Please have look, partly because I put in more exercises than I discussed in class, in case you want to drill a bit on validity. I will pick up some of the stuff at the end, on if-then-else, tomorrow. Lecture
notes for the first seven lecture on programming in ACL2 are coming along, and
should be up later this week.
Change of office hours for Prof. PucellaMon, 26 Jan 2009 00:08:00 ESTRiccardo Pucella
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html/Mon--26-Jan-2009-Change-of-office-hours-for-Prof.-Pucella
Prof. Pucella has changed his office hours to Mondays from
14h00-16h00.
Homework 2 is outSun, 25 Jan 2009 00:08:00 ESTRiccardo Pucella
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html
http://www.ccs.neu.edu/home/riccardo/courses/csu290-sp09/index.html/Sun--25-Jan-2009-Homework-2-is-out
Homework 2 is available from
the <a href="http://www.ccs.neu.edu/course/csu290/assignments.html">course
web page</a>.