The Concept of Data: Simple Data Types  15  Figure 2.c  Syntax diagram for  SimpleType  Figure 2.b  Type taxonomy of simple data types  The two kinds of simple types in Pascal are ordinal types and the  real type. An ordinal type is either defined by you (called an enumerated  or subrange type)  or is denoted by one of the three predefined ordinal  type identifierS-Boolean, Integer, or Char. The real type is denoted  by the predefined type identifier Real.  An enumerated type is characterized by the set of its distinct values,  upon which a linear ordering is defined. The values are denoted by  identifiers in the definition of the type. A subrange type specifies a  minimum and maximum value from a previously declared ordinal type  to create a new ordinal type.  Enumerated and subrange types are  described in Chapter 5.  An ordinal data type describes a finite and ordered set of values. These  values are mapped onto  ordinal numbers  0,  I,  2,  ... , except for the  ordinal numbers of integers which are mapped onto themselves. Each  ordinal type has a minimum and maximum value. Except for the  minimum value, each value of an ordinal type has a  predecessor  value.  Except for the maximum value, each value of an ordinal type has a  successor  value.  2.A.  Ordinal  Data Types  I  Simple Data Types  I  /  ~  Real  Ordinal Data Types  /  ~  ~  Enumerated  Predefined Ordinal  Subrange  Data Typ/ta t  T~Data  Types  Boolean  Integer  Char  ---'l---------I.~I  OrdinalType  Ir---------~--·  ~-----_.).I  RealTypeldentifier  Ir------~J 