Modal Logic 2
The notion of a Kripke Frame and an accessability relation
Structural properties of an accessability relation: reexivity,
transitivity, symmetry and more
Truth in a Kripke frame
The logics K , T , S4 and S5
en adding generalizations to an argument, you have a choice of several that will
ke the argument valid or cogent. The principle of charity in this case
ing reasonable generalizations rather than ones known to be false.
Modal Logic 1
Propositional modal Languages
Interpretations of modal operators
The notion of a structure and a valuation
Simple semantics for S5
Logical truths of S5
A simple language of propositional logic:
A := p | A
Example Passage #1
Ive posted solutions to HW #3 & HW #4.
Quiz #3/#4 will be returned today (end of class)
Grades were slightly better on the re-do
HW #5 due this Thursday
7 problems from Chapter 5
I will be posting Extra Cre
Sample Passages #2, 4, 5, 6, and 7 Reconstructions
April 7, 2011
2. The second passage reads as follows:
Letter to the editor: In regard to your editorial, Crime bill wastes billions, let me set you straight. Your paper
opposes mandatory life sentences fo
What is a theory?
First attempt: A theory is a set of claims that hang together in a logically
Second attempt: A theory is a deductively closed set of sentences
A set of senten
HW #6 will be returned on Thursday
Our nal quiz will be on Thursday as well
This will involve several questions about
Take-home nal: TBA on 4/28. To be due 5/12.
+ More extra-credit (TBA on 4/28; TBD
Metaphysics of Modality !
Lecture 1 !
Lukas Skiba firstname.lastname@example.org!
Why care about modality?!
Preliminary remarks and distinctions!
David Lewiss metaphysics of modality!
Modality in Everyday Life!
We often assert that something is
f e writing and rhetoncal wntmg.
IV As its name Reconstructing is wntmg m which 1
suggests, descriptive writing Arguments e
describes some event or situation. The author makes no ent s from.to nar gu me ntse . 7
ts are surprising . . ,
rl yi ng th e gu n ar gu m en
ics un de
hly ten th ou sa nd
ap pa lli ng : w e ha d roug
, th er e w er e 18 ,7 14
itish ha d forty. In 19 78
. Th e Br
ith ha nd gu ns . In th at
pe rc en t w er e ki
The Curve (so far)
A rg um en t 7. 7b
First, IHshouldis point ed. (Ethat all grades are stored in the sakai
unt)las out P)
an na n
e no be
2. All ju dg es w ho ar
na n IS m ed io cr e. (1 ),