Roland Backhouse 
Program Construction [PDF ebook] 
Calculating Implementations from Specifications

Most texts on logic or discrete math fail to show why math and logic are fundamental tools for programmers. Program Construction illustrates the importance of math and logic to programming, providing a complete, self-contained account of the principles of logical reasoning. Designed specifically so users can construct programs that meet their specifications, the book details program construction principles in a straightforward fashion, avoiding overly complicated theory, and then illustrating each with convincing examples.