Validity and Soundness
Section 1.6 (p. 17-23) will introduce you to the concept of validity – the term for when the conclusion of an argument follows from its premises. Pay careful attention to the difference between validity and soundness, the concept introduced in section 1.7. All sound arguments are valid, but not all valid arguments are sound. Remember that premises do not have to be true for an argument to be valid.
Complete Exercise 5, checking your answers against the key on pages 209-210.