Implicit_Typing

 By default, all variables with names beginning with I, J, K, L, M,
 or N are assumed to be integer variables.  Variables beginning with
 any other letter are assumed to be real variables.

 Names beginning with a dollar sign ($) are implicitly INTEGER.

 You can override the default data type implied in a name by
 specifying data type explicitly in either an IMPLICIT statement or
 a type declaration statement.

 Note:  You cannot change the implicit type of a name beginning with
 a dollar sign in an IMPLICIT statement.