University of California, San Diego: Edward Bender and S. Williamson's "Arithmetic, Logic and Numbers: Logic"
Read example 15 on page Lo-19. Here you read about the use of quantifiers together with the use of logic operations, such as AND, OR.
As you study and read, you should THINK about the material, both on what it means in relation to what you already know and how it relates to other topics you have studied. To help you think about the material, you should look at the exercises, even if the instructions don't explicitly state this.