Implementations
shall provide a user-selectable mode in which the accuracy and other
numeric performance requirements detailed in the following subclauses
are observed. This mode, referred to as the 
strict mode, may or
may not be the default mode; it directly affects the results of the predefined
arithmetic operations of real types and the results of the subprograms
in children of the Numerics package, and indirectly affects the operations
in other language defined packages. 
Implementations
shall also provide the opposing mode, which is known as the 
relaxed
mode. 
 
   Either mode may be the default mode.