Sinposis

A PROGRAM'S TYPE DESCRIBES ITS BEHAVIOR. DEPENDENT TYPES ARE A FIRST-CLASS PART OF A LANGUAGE, AND ARE MUCH MORE POWERFUL THAN OTHER KINDS OF TYPES; USING JUST ONE LANGUAGE FOR TYPES AND PROGRAMS ALLOWS PROGRAM DESCRIPTIONS TO BE AS POWERFUL AS THE PROGRAMS THEY DESCRIBE. THE LITTLE TYPER EXPLAINS DEPENDENT TYPES, BEGINNING WITH A VERY SMALL LANGUAGE THAT LOOKS VERY MUCH LIKE SCHEME AND EXTENDING IT TO COVER BOTH PROGRAMMING WITH DEPENDENT TYPES AND USING DEPENDENT TYPES FOR MATHEMATICAL REASONING. READERS SHOULD BE FAMILIAR WITH THE BASICS OF A LISP-LIKE PROGRAMMING LANGUAGE, AS PRESENTED IN THE FIRST FOUR CHAPTERS OF THE LITTLE SCHEMER.