anchor.diff:  
   For every class [classname]`X`:
   
  +[start=1]
   . For each superclass [classname]`Y` of [classname]`X`, the group [classname]`Y` contains all constraints of the group [classname]`Y` of [classname]`Y`
   _this rule prepares formal concepts for recursive discovery_
   
   [tck-testable]
   --
  +[start=2]
   . The group [classname]`X` contains the following constraints:
   [tck-ignore]#group X is a group used on sequences redefining the default group on a class (see <<constraintdeclarationvalidationprocess-groupsequence-redefiningdefaultgroup>>)#
   .. every constraint declared by the class [classname]`X` which does not declare a group or does declare the group [classname]`Default` explicitly.
  
positive.code: [tck-ignore]#_every constraint hosted by any superclass of X and marked as belonging to the group Z_#
  --
  
  . [tck-testable]#For every interface [classname]`Z` annotated [classname]`@GroupSequence`, the group [classname]`Z` contains every constraint belonging to every group declared by the [classname]`@GroupSequence` annotation.#
  _defines the composition side of group sequence but does not define the ordering behavior of sequence (see <<constraintdeclarationvalidationprocess-groupsequence-groupsequence>>)_
  
  
negative.code: [tck-ignore]#_this rule is necessary in case Y redefines the group Default_#
  --
  
  [start=4]
  . [tck-testable]#If [classname]`X` does have a [classname]`@GroupSequence` annotation, the group [classname]`Default` contains every constraint belonging to every group declared by the [classname]`@GroupSequence` annotation.#
  _this rule describes how a class can redefine the group Default for itself (see <<constraintdeclarationvalidationprocess-groupsequence-redefiningdefaultgroup>>)_
  ** [tck-testable]#the [classname]`@GroupSequence` annotation must declare the group [classname]`X`#
  
  [tck-testable]
  --
  [start=5]
  . For every interface [classname]`Z`, the group [classname]`Z` contains the following constraints:
  [tck-ignore]#_this rule defines how non Default groups are defined_#
  .. every constraint declared by the interface [classname]`Z` which does not explicitly declare a group or does declare the group [classname]`Default` explicitly.
  