Inference Rules
1. For part (a):
- Given: Linda owns a red convertible.
- Given: Everyone who owns a red convertible has gotten at least one speeding ticket.
- By universal instantiation, "Linda" fits the "everyone" category.
- By modus ponens on "Linda owns a red convertible" and the universal statement, conclude "Linda has gotten at least one speeding ticket."
- By existential generalization, conclude "Someone in this class has gotten a speeding ticket."
2. For part (b):
- Given: Five roommates Melissa, Aaron, Ralph, Veneesha, and Keeshawn each have taken discrete mathematics.
- Given: Every student who has taken discrete mathematics can take algorithms.
- By universal instantiation applied to each roommate and modus ponens, conclude each can take algorithms.
- By conjunction, conclude all five can take a course in algorithms.
3. For part (c):
- Given: All movies produced by John Sayles are wonderful (universal statement).
- Given: John Sayles produced a movie about coal miners.
- By universal instantiation, this specific movie is wonderful.
- By existential generalization, there is a wonderful movie about coal miners.
4. For part (d):
- Given: Someone in this class has been to France (existential statement).
- Given: Everyone who goes to France visits the Louvre (universal statement).
- By existential instantiation, take that someone who has been to France.
- By universal instantiation and modus ponens, conclude that person visited the Louvre.
- By existential generalization, conclude that someone in this class has visited the Louvre.
Each step uses standard rules of inference: universal instantiation, existential instantiation, modus ponens, conjunction, and existential generalization.