What does the term "zero-day vulnerability" refer to in

Statements: F > G = J ≤ I = L > M ≥ K = N

Conclusion

I: N < I

II: L ≥ G

Statement: J < L; J ≥ H > K; L ≥ F > M

Conclusion:

I. K ≥ L

II. F ≥ J

Statements:  M = R ≥ S , N = O > Q, Q > W = A < S

Conclusions :I. N ≥ S    II. W > R   III. O ≤ S

Which of the following expressions will be true if the expression P > Q = R < S = T ≤ U = V is definitely true?

Statement: W > S; D > V > R; S > D

Conclusion:

I.W > R

II. W > V

Statements: A < B; C = D; B >E ≥ C

Conclusions:

I. A < C

II. E = D

Statements: A > B > C, C < D > E, E = F > G

Conclusion:

I. C = G

II. A > F

Which of the following will be definitely true if the given expression O > B ≥ E > Z ≥ Y > P = X ≤ J > W ≤ N is definitely not true?

Statements: D < O = Q > U < I ≤ R; K ≥ O = I; R > H ≥ G

Conclusions:

I. R > O

II. K > U

III. H ≥ Q

Statements: F % W, W © R, R @ M, M $ D

Conclusions: