5. Which one of the following is equivalent to [tex][tex]$p \vee q$[/tex][/tex]?

A. [tex]$\neg p \rightarrow q$[/tex]
B. [tex]$\neg(\neg p \vee \neg q)$[/tex]
C. [tex][tex]$\neg\left(p \wedge q\right)$[/tex][/tex]
D. [tex]$\neg p$[/tex]



Answer :

To determine which of the expressions is equivalent to [tex]\( p \vee q \)[/tex] (which states "p or q"), let's analyze each of the given options in detail:

Option A: [tex]\( \neg p \rightarrow q \)[/tex]

To understand this, recall that the implication [tex]\( \neg p \rightarrow q \)[/tex] can be rewritten as [tex]\( \neg(\neg p) \vee q \)[/tex] using logical equivalences. Simplifying [tex]\( \neg(\neg p) \)[/tex] gives us [tex]\( p \vee q \)[/tex]. Therefore, [tex]\( \neg p \rightarrow q \)[/tex] is indeed equivalent to [tex]\( p \vee q \)[/tex].

Option B: [tex]\( \neg(\neg p \vee \neg q) \)[/tex]

This is the negation of the disjunction [tex]\( \neg p \vee \neg q \)[/tex]. According to De Morgan's laws, [tex]\( \neg(\neg p \vee \neg q) \)[/tex] is equivalent to [tex]\( p \wedge q \)[/tex] (the conjunction "p and q"), which is logically different from [tex]\( p \vee q \)[/tex].

Option C: [tex]\( \neg\left(p \wedge q\right) \)[/tex]

According to De Morgan's laws again, [tex]\( \neg(p \wedge q) \)[/tex] is equivalent to [tex]\( \neg p \vee \neg q \)[/tex]. This is clearly not the same as [tex]\( p \vee q \)[/tex].

Option D: [tex]\( \neg(p) \)[/tex]

This option is just the negation of [tex]\( p \)[/tex], which is unrelated to [tex]\( q \)[/tex]. Hence, it cannot be equivalent to [tex]\( p \vee q \)[/tex].

Given these analyses, the expression that is equivalent to [tex]\( p \vee q \)[/tex] is:

A. [tex]\( \neg p \rightarrow q \)[/tex]

Thus, the correct choice is Option A.