Задача
Two segments are given on the number line: P = [8.39] and Q = [23.58]. Choose from the proposed options such a segment A that the logical expression
((x ∈ P) /\ (x ∈ < em>A) ) → ((x ∈ Q) /\ (x ∈ A) )
is identically true, that is, it takes the value 1 for any value of the variable x.
1) [5, 30] ; 2) [15, 40] 3) [20, 50] 4) [35, 60]