[Math] Writing proposition with connectives and laws of logic

computer sciencelogicpropositional-calculus

Question 1): Pei Ann has been dealt two cards from a standard 52 card deck. She holds one in her left hand and one in her right.

Let $p$ be the proposition "The card in Pei Ann's left hand is an ace".

Let $q$ be the proposition "The card in Pei Ann's right hand is an ace"

Let $r$ be the proposition "The card in Pei Ann's left hand is a club".

Let $s$ be the proposition "The card in Pei Ann's right hand is a club".
Write propositions (using just $p, q, r, s$ and logical connectives) corresponding to the following sentences.

  1. Pei Ann doesn't have two aces.
  2. Pei Ann has at least one club.
  3. Pei Ann has the ace of clubs and another club.

Question :2) Show that $(\neg p \lor \neg q) \rightarrow \neg q \equiv p \lor \neg q$ using the laws of logic.

These are two of the questions for my quiz that I had trouble doing.

For question number (1) I am not sure what a standard 52 card deck is, not a cards fan.
I could solve it for the first sentence "Pei Ann doesn't have two aces" I think. I came with $\neg (p \land q)$. Is it correct? For the second sentence I am not exactly sure. Could it be $(p \rightarrow r) \lor (q \rightarrow s)$?
For the third sentence I have no idea how to even begin.

For question number (2) I got to this result $\neg q \lor p \land q$ after applying various logic laws. I could not get it to $p \lor \neg q$.

Any help will be appreciated.

Best Answer

Q1.

-(sentence 1) Pei Ann doesn't have two aces. : $\neg p \land \neg q$

-(sentence 2) Pei Ann has at least one club. : $r \lor s$

-(sentecne 3) Pei Ann has the ace of clubs and another club. : $ (p \land s) \lor (q \land r)$

Q2.

show that (¬p∨¬q)→ ¬q ≡ p∨¬q

(¬p∨¬q)→ ¬q ≡ ¬(p $\land$q) → ¬q ≡ (p $\land$q) $\lor$ $\neg q$ ≡ (p $\lor$ ¬q) $\land$ (q $\lor$ ¬q) ≡ (p $\lor$ ¬q)