Homework for Philosophy 270, Fall 2011

Homework on §1.4—assigned Fri 9/2 and due Mon 9/5

(to PDF format)

Define entailment in terms of truth values and possible worlds for the specific case of two premises—that is, complete the following:

φ, ψ ⊨ χ if and only if ...

Give the definition in both positive and negative form (so complete the pattern above twice).