A statement that we don't know is true or false.
Example: x + 2 = 3
Until we know the value of "x", we don't know if "x + 2 = 3" is true or false.
• If x is 1 then "x + 2 = 3" is TRUE
• If x is 2 then "x + 2 = 3" is FALSE
• etc
Example: z > 4
Until we know the value of "z", we don't know if it is greater than 4 or not.
If z is 5 then "z > 4" is TRUE
If z is 2 then "z > 4" is FALSE
etc