7.8.x. Exercise questions

Use the system of derivations to find structures dividing premises from conclusions in the cases below. You will need to use the rule UG+.

1. ∀x ¬ ∀y ¬ Rxy / ∀x ¬ Rxx
2. ∀x ¬ ∀y Rxy / ¬ ∀x Rxa
3. ∀x ¬ ∀y Rxy / ∀x ¬ Rax
Glen Helman 15 Aug 2006