3.5 Symbolic Arguments

• A symbolic argument consists of several premises and a conclusion.

  If the car is a mustang then it is fast.   <- premise 
  The car is a mustang      <- premise 
  Therefore it is fast.    <- Conclusion
      

• If we can show (P₁ ^ P) -> C is a tautology, then the argument is valid.
• Do This.
• We know some arguments are valid (P155)
  • p->q, p, therefore q, Law of Detachment.
  • p->q, ~q therefore not p, Law of Contraposition
  • p->q, q->r therefore p->r, Law of Syllogism
  • pVq, ~p therfore q, Disjunctive Syllogism
• And some arguments are false:
  • p->q, q, therefore p,Fallacy of Converse.
  • p->q, ~q therefore ~p, Fallacy of the Inverse.
• Problems 1-30 Page 159
• 34, 37,