Wiki-ch2: Difference between revisions
Line 1: | Line 1: | ||
= Additional Wiki pages for Chapter 2 = | = Additional Wiki pages for Chapter 2 = | ||
== Models == | |||
Watch a short podcast what first-order models look like. | |||
<mediaplayer>http://youtu.be/4a3mXelw7H4</mediaplayer> | |||
== Truth tables == | == Truth tables == |
Revision as of 15:09, 11 April 2013
Additional Wiki pages for Chapter 2
Models
Watch a short podcast what first-order models look like.
<mediaplayer>http://youtu.be/4a3mXelw7H4</mediaplayer>
Truth tables
The following material is an adapted form of material created by student participants of the project e-Learning Resources for Semantics (e-LRS). Involved participants: Lisa, Marthe, Elisabeth, Isabelle.
Truth tables for connectives
AND (∧)
Symbol: ∧
Sentence: Harry is a student and Snape is a teacher.
Formulae: student(harry) ∧ teacher(snape)
Truthtable AND
OR (∨)
Symbol: ∨
Sentence: Harry is a student or Snape is a teacher.
Formulae: student(harry) ∨ teacher(snape)
Truthtable OR
IF/THEN (⊃, →)
Symbol: ⊃, → (Note: We use the symbol ⊃ in the textbook as it is more common in the logical literature.)
Sentence: If Harry is a student then Snape is a teacher.
Formula: student(harry) ⊃ teacher(snape)
Truthtable IF/THEN
NOT (¬)
Symbol: ¬
Sentence: Harry is not a student.
Formula: ¬student(harry)
The original formula has to be false for the overall statement to be true.
Example: Only if student(harry) is false, ¬student(harry) is true.
Truthtable NOT
Truth tables for complex formulae
Truth tables are also useful to compute the truth value of complex formulae. This is shown in the following podcast, created by Lisa Günthner.
<mediaplayer>http://www.youtube.com/watch?v=ZWdltj5Mqdc</mediaplayer>