Just to re-iterate what was announced in class today: Â neither Paul’s nor Pete’s section will meet on Tuesday, February 22nd. Â That means that our next class meeting will not be until Wednesday, February 23rd.
HW3 answer key now available
The key for homework #3 has now been posted to the readings page.
HW2 answer key: available
The key for homework #2 has now been posted to the readings page.
HW3, Part IV Clarification
Several of you have asked for clarification regarding Part IV (‘A Puzzle about English Conditional Sentences’) of your third homework assignment. Â Having read the directions again, they do seem a bit unclear. Â Here is what is being asked of you:
In Part A, you should produce a PropL formula that translates the English sentence in (12).
(12) Â It’s not true that if Darwin was wrong, then God exists.
Then, construct a truth table for that PropL formula.
In Part B, you should use the truth-table method that we discussed in class to determine the entailment relationships that exist between the PropL translations of  i) (12) and its antecedent, ii) (12) and its consequent, iii) (12) and the negation of its antecedent, and iv) (12) and the negation of its consequent.  In other words, this part of the assignment asks you to only consider the entailment relations that exist amongst the relevant PropL formulas.  Note that in order to complete this task, you will likely have to add some new columns to your truth table from Part A.  Also, a terminological note:  remember that the ‘antecedent’ of a conditional sentence is the embedded sentence that immediately follow if, while the ‘consequent’ of a conditional sentence is the embedded sentence that immediately follows then.
In Part C, you should ask whether the entailment relations that you identified in Part B correctly represent your intuitions about the information that the English sentence (12) manages to convey. Â In other words, this part of the assignment asks to you consider whether the meaning of your PropL translation does in fact adequately represent the actual meaning of (12). Â If you feel that it does not, then you should explain the problem(s) as precisely as you can, making sure to describe what (12) actually does convey.
Handout on Semantic Relations Amongst Sentences
Here’s a PDF handout summarizing today’s in-class discussion of semantic relations amongst sentences, and how they can be identified using propositional logic truth tables:
Propositional Logic Handout
Here’s a PDF version of the handout on propositional logic that was distributed in class today. Â For those of you in the A1 section (Pete’s section), this version also contains the full truth table for example (3)–once you’ve completed it on your own, you can check your results against this version.
HW3 (due 2/14 @ beg. of class)
Your third homework assignment is now available for download–just click on the link below for a PDF version.  It will be due on Monday, February  14, at the beginning of class.
Reading for W 2/9 & F 2/11: Löbner §4.2-4.3 (pgs. 62-73)
I’ve posted a short excerpt from another Semantics textbook (written by Sebastian Löbner) in the “Readings” section of the website.  It discusses how certain semantic relationships between sentences, such as entailment, can be modeled in Propositional Logic.  Please read this excerpt for W 2/9 and F/211.
(Note:  §4.2 of the reading uses some terms that you won’t be familiar with, such as “CoU” and “Principle of Polarity”.  Don’t worry too much about these…just make sure that you understand the terms “contingent”, “logically true”, and “logically false”.)
Definition of ‘denial’
A few of you asked if I could re-state the definition of denial, since it is relevant to Part I of your current homework assignment. Â Here it is:
Sentence A is the denial of sentence B: it is impossible for A and B to both be true, and it is also impossible for A and B to both be false. Â (In other words, A and B have the opposite truth conditions.)
Handout on ‘all’, ‘most’, ‘some’, and their implicatures
Here’s a PDF version of the handout entitled “All, most, and some: A case study in implicature”, which we (Pete’s section) worked through in today class: