GATE | GATE-CS-2014-(Set-1) | Question 11
Consider the statement
“Not all that glitters is gold”
Predicate glitters(x) is true if x glitters and predicate gold(x) is true if x is gold. Which one of the following logical formulae represents the above statement?
The statement “Not all that glitters is gold” can be expressed as follows :
¬(∀x(glitters(x)⇒gold(x)) … (1)
Where ∀x(glitters(x)⇒gold(x) refers that all glitters is gold. Now ,
As we know, A⇒B is true only in the case that either A is false or B is true. It can also defined in the other way :
A⇒B=¬A∨B (negationA or B ) … (3)
So Answer is (D) .
This solution is contributed by Nirmal Bharadwaj.