What is Cr (a ∩ b) equal to if u = R, a {x ∩ x < 0 or X > 2 =, B = {X - 1 < x < 3 =? Please tell me the process, thank you

What is Cr (a ∩ b) equal to if u = R, a {x ∩ x < 0 or X > 2 =, B = {X - 1 < x < 3 =? Please tell me the process, thank you


Complete set u = R, set a {x | x < 0 or X > 2}, B = {x | - 1 < x < 3},
∴(A∩B)={x|-1



The complete set u = R, set a = {X / X less than or equal to A-1}, set B = {X / x greater than A-2}, set C = {X / X less than 0 or x greater than or equal to 4}
If the complement of a and B belongs to C, find the value range of real number a


∵ a = {x | x ≤ A-1}, B = {x | x > A-2}, C = {x | x < 0, or X ≥ 4}
A ∪ B = {x | A-2 < x, or X ≤ A-1},
And ∵ for any a belonging to the complete set R, A-2 is always less than A-1
A ∪ B = {x | A-2 < x, or X ≤ A-1} = R
The complements of (a ∪ b) = &;
The complement of ∪ B belongs to C, and an empty set is a subset of any set
The value range of a is the complete set R