J.4 The Constrained Attribute
Static Semantics
For every private subtype 
S, the following attribute is defined: 
Yields the value False if S denotes an unconstrained nonformal private 
subtype with discriminants; also yields the value False if S denotes 
a generic formal private subtype, and the associated actual subtype is 
either an unconstrained subtype with discriminants or an unconstrained 
array subtype; yields the value True otherwise. The value of this attribute 
is of the predefined subtype Boolean. 
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