Set Theory

Exercises

1. Compute $A \cup B$, $A \cap B$ for sets like $A = (1,3)$, $B = (2,4)$.

2. Describe and sketch the regions given by the following sets:

   • a) ${(x, y) : x < 0}$
   • b) ${(x, y) : y = -1}$

   • c) ${(x, y) :

     x

     \geq 1}$

   • d) ${(x, y) : x \geq 0,

     y

     < 1}$

     • e) ${(x, y) :

       x - 1

       \geq 0, y = 1}$

     • f) ${(x, y) :

       x - 2

       \leq 0,

       y - 3

       > 0}$

See

• Order Theory