PHL111 Valid Reasoning, current assignments
NOTE: please do me the favor of
They are anonymous. I'm trying to save paper for the class and so
am using the online evals. However, that means I depend on you to
take the time to do them. It's only two minutes! I appreciate it
greatly if you can do them.
- logging into Angel and
- Going to the Learning Modules
- Clicking on "Repository - Philosophy Department Respository"
- Completing the online evaluations.
I'll have office hours from 9:00 a.m. -- 10:00 a.m., and
from 1:00 p.m. to 3:30 p.m.
I was asked for some practice problems. Here are a few.
I've posted some of the answers here.
Try to prove these theorems:
Make an informal model to illustrate the following are invalid:
- Conclusion: ((∀x(Fx → Gx) ^ ∃x(Fx ^ Hx)) → ∃x(Gx ^ Hx))
- Conclusion: (∀x(Fx ↔ Gx) → (∃xFx ↔ ∃xGx))
Translate the following:
- Premises: ∀x(Fx → Gx), ¬Fa. Conclusion: ¬Ga.
- Premises: ∀x(Fx → Gx), Ga. Conclusion: Fa.
- All and only orcs eat kobolds.
- All orcs are either from Mordor or Moria.
- Something is an orc from Moria that eats raw fish.
- Every orc is taller than Frodo.
- Frodo is taller than some kobold.
- No kobold is taller than Frodo, but some dwarves are taller than Frodo.
- Morder is a worse place to spend Spring break than Rivendell.
- [See if you can do this with the same predicate you used in
problem 7:] Mordor is the worst place to spend Spring break.
Final exam, 8:00 a.m. -- 10:00 a.m.
Watch all five of these
videos before you start studying for the final. They are
short and they will do you a ton of good.
Tentative/expected Assignments (subject to revision)