PHIL1012 Introductory Logic
Problem Set 7
1. (4 marks) Using a tree, determine whether the following argument is valid. If the argument is not valid, read off from your tree (and indicate the path from which you are reading it off) a model in which the premises are true and the conclusion false.
∀y(Gy → F y)/∃y(F y ∧ Gy)