  This book has eleven chapters. Chapter one describes all types of natural
class of intervals and the arithmetic operations on them. Chapter two
introduces the semigroup of natural class of intervals using R or Zn and study
the properties associated with them. Chapter three studies the notion of rings
constructed using the natural class of intervals. Matrix theory using the
special class of intervals is analyzed in chapter four of this book. Chapter
five deals with polynomials using interval coefficients. New types of rings of
natural intervals are introduced and studied in chapter six. The notion of
vector space using natural class of intervals is built in chapter seven. In
chapter eight fuzzy natural class of intervals are introduced and algebraic
structures on them is built and described. Algebraic structures using natural
class of neutrosophic intervals are developed in chapter nine.Chapter ten
suggests some possible applications. The final chapter proposes over 200
problems of which some are at research level and some difficult and others are
simple.
