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1 Context Expressions and Logic
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1.1 Overview
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UCM provides two distinct usage of ContextValues in a ContextGraph:


The ability to associate ContextValues to objects
The ability to resolve objects by expressing ContextValues for a specific
business situation
These two provisions in UCM are referred to as “assigned context” and “applied
context” (respectively above).
The mechanism to facilitate these is based on well know predicate logic. Within
UCM’s predicate logic, a set of ContextClauses are specified to support
assignment and application of ContextValues. These Clauses are encompassed
within a ContextExpression.
This section uses the following ContextGraph as an example. The letters
represent Ids of ContextNodes from a fictitious ID scheme from “Letters.org”:
D
B
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C
F
A
I
H
G
J
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The metadata for this ContextGraph is as follows:
Note: need to add to ContextGraph meta data.
 URNUUID = URN:UUID: f224def0-7a77-45fc-8806-682ba7e31f26
 Version = 1.0
 ContextNodeIDSchemeURI = http://www.letters.org
 ContextNodeIDShemeAgencyName = Letters
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1.2 Context Clauses
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The following is a UML logical sketch diagram of ContextExpressions:
ContextExpression
ContextClause
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+contextgraphid
+contextgraphversion
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1
1
SimpleContextClause
+predicate
+contextnodeid
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CompoundContextClause
+operand
There are two concrete types of ContextClauses – SimpleContextClause and
CompoundContextClause. A CompoundContextClause provides for an arbitrarily
complex ContextClause through recursion.
A ContextExpression contains a single ContextClause. A ContextExpression also
contains the ID and version of the ContextGraph to which it refers.
A ContextExpression has the following lexical notation:
[<ContextGraph URNUUID>”,”<ContextGraph version>”,”<ContextClause>]
Note: grammar to be defined formally.
A SimpleContextClause is a ContextClause with one predicate and one
ContextNode ID.
A predicate has the following possible values (with notation):
 Equal to (=)
 Not equal to (!=)
 Greater than (>)
 Less than (<)
 Greater than or equal to (>=)
 Less than or equal to (<=)
A SimpleContextClause has the following lexical notation:
(<predicate>”,”<ContextNode ID>)
A CompoundContextClause is a ContextClause with two (referred to as “first”
and “second”) ContextClauses (either SimpleContextClause or
CompoundContextClause) and one operand.
An operand has the following possible values (with notation):
 Intersection (&&)
 Union (||)
 Exclusion (!)
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A CompoundContextClause has the following lexical notation:
((<ContextClause>)<operand>(<ContextClause>))
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1.3 Assigned Context and Contextualized
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Assigning context is the action of specifying a ContextExpression as part of an
object. This object is called a Contextualized object, or simply, a
“Contextualized”. An example of a Contextualized is a Business Information
Entity (BIE). Other types of objects may be Contextualized.
The semantics of the predicates and operands are determined by the usage of
the ContextClauses (assigned or applied).
Assigning context is accomplished by defining a ContextExpression whose
ContextClause can be resolved to a set of ContextValues in a specific
ContextGraph through processing, and specifying the ContextExpression as an
intrinsic part of the Contextualized.
Contextualized
+ContextExpression
«BIE»
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The set of ContextValues which can be resolved from the ContextExpression’s
ContextClause indicates which ContextValues are relevant to the Contextualized.
A Contextualized must contain one ContextExpression.
The following are the semantics of the predicate values within a
SimpleContextClause when assigning context:
 Equal to (=) - The Contextualized is associated with the ContextNode ID.
The following ContextExpression with a SimpleContextClause indicates
that the Contextualized is assigned with ContextValues C:
[URN:UUID: f224def0-7a77-45fc-8806-682ba7e31f26,1.0,(=,C)]
 Greater than (>) - The Contextualized is associated with all ContextValues
of all ancestor ContextNodes of the ContextNode ID.
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The following ContextExpression with a SimpleContextClause indicates
that the Contextualized is assigned with ContextValues A,B,G:
[URN:UUID: f224def0-7a77-45fc-8806-682ba7e31f26,1.0,(>,H)]
 Less than (<) - The Contextualized is associated with all ContextValues of
all child ContextNodes of the ContextNode ID.
The following ContextExpression with a SimpleContextClause indicates
that the Contextualized is assigned with ContextValues I,J:
[URN:UUID: f224def0-7a77-45fc-8806-682ba7e31f26,1.0,(<,H)]
 Greater than or equal to (>=) - The Contextualized is associated with all
ContextValues of all ancestor ContextNodes of the ContextNode ID and
the ContextValue of the ContextNode ID.
The following ContextExpression with a SimpleContextClause indicates
that the Contextualized is assigned with ContextValues A,B,G,H:
[URN:UUID: f224def0-7a77-45fc-8806-682ba7e31f26,1.0,(>=,H)]
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Less than or equal to (<=) - The Contextualized is associated with all
ContextValues of all child ContextNodes of the ContextNode ID and the
ContextValue of the ContextNode ID.
The following ContextExpression with a SimpleContextClause indicates
that the Contextualized is assigned with ContextValues H,I,J:
[URN:UUID: f224def0-7a77-45fc-8806-682ba7e31f26,1.0,(<=,H)]
The following are the semantics of the operand values of a
CompoundContextClause when assigning context:
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Intersection (&&) - The Contextualized is associated with all
ContextValues which are common to the two ContextClauses.
The following ContextExpression with a CompoundContextClause
indicates that the Contextualized is assigned with ContextValues H:
[URN:UUID: f224def0-7a77-45fc-8806-682ba7e31f26,1.0, (=,H)&&(<=,B)]

Union (||) - The Contextualized is associated with all ContextValues
specified in the two ContextClauses.
The following ContextExpression with a CompoundContextClause
indicates that the Contextualized is assigned with ContextValues
H,C,D,E,F:
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[URN:UUID: f224def0-7a77-45fc-8806-682ba7e31f26,1.0,(=,H)||(<=,C)]
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Exclusion (!) - The Contextualized is associated with all ContextValues
specified in the first ContextClause minus the ContextValues specified in
the second ContextClause.
The following ContextExpression with a CompoundContextClause
indicates that the Contextualized is assigned with ContextValues C,E,F:
[URN:UUID: f224def0-7a77-45fc-8806-682ba7e31f26,1.0,(<=,C)!(=D)]
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1.4 Applying Context
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Note: no examples in this section yet of resolved Contextualizeds.
The application of context for a specific business situation is the action of
resolving a set of Contextualized objects from a set of ContextExpression.
The application of context is accomplished by defining a single
ContextExpression and processing its ContextClause over the identified
ContextGaph. A ContextClause for applied context acts a query, and is resolved
into a set of Contextualizeds.
The following are the semantics of the predicate values of a
SimpleContextClause when applying context:
 Equal to (=) - The set of Contextualizeds which are associated with the
ContextValue of the ContextNode ID.
 Not Equal to (!=) - The set of Contextualizeds which are not associated
with the ContextValue of the ContextNode ID.
 Greater than (>) - The set of Contextualizeds which are associated with all
ContextValues of all ancestor ContextNodes of the ContextNode ID.
 Less than (<) - The set of Contextualizeds which are associated with all
ContextValues of all child ContextNodes of the ContextNode ID.
 Greater than or equal to (>=) - The set of Contextualizeds which are
associated with all ContextValues of all ancestor ContextNodes and the
ContextValue of the ContextNode ID.
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 Less than or equal to (<=) - The set of Contextualizeds which are
associated with all ContextValues of all child ContextNodes and the
ContextValue of the ContextNode ID.
The following are the semantics of the operand values of a
CompoundContextClause when applying context:
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Intersection (&&) - The set of Contextualizeds which are members of both
sets of resolved Contextualizeds from the two ContextClauses.
 Union (||) - The set of Contextualizeds which are members of either set of
resolved Contextualized from the two ContextClauses.
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Exclusion (!) - The set of Contextualizeds which are members of the set of
resolved Contextualized from the first ContextClause minus the members
of the set of resolved Contextualized from the second ContextClause.