Review
We have the following De Morgan's laws.
1) First law
Where:
¬ means a negation
∧ is the and symbol
∨ is the or symbol
2) Second law
In our problem we have following statement:
We can make the following identification:
[tex]\begin{gathered} p=\lbrace7-1=6\rbrace \\ q=\lbrace17+6\ne4\rbrace \end{gathered}[/tex]
With the last definitions/identification we can rewrite the statement in the following way:
And we want to find the negation of the statement, i.e. we want to know:
In order to that we can use the first De Morgan law and write:
Now, the negations of p and q are:
Using the last equations and the first De Morgan law we have that:
Finally, we must translate the last equation to words taking in account that ∨ = or, doing that we find that:
Answer
We see that the correct option is letter B.
