I added part 4 to the homework to cover the propositional logic discussion. It is now due on 3/5
The rationale is that your midterm will cover all topics from homework 1 and 2. I will make the solutions for homework
available on 3/5.
ps: Here is what is added:
Part 4(Added new):
- Consider the following inference rule: if we know A V B; and we know ~A, we can derive B. Show that this inference is sound using truth-table method. Is this inference complete? Can you show that this is a special case of resolution?
- (Problem 7.9 from the text book) Given the following, can you prove that the unicorn is mythical? How about magical? Horned?
"If the unicorn is mythical, then it is immortal, but if it is not mythical, then it is a mortal animal. If the unicorn is either immortal or a mammal, then it is horned. The unicorn is magical if it is horned."