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Interface to the Application Layer
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Input:
+ queries
+ questions for explanations

Output
+ query results as triples plus queryID
+ explanations as EXPL graphs


Methods:

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1. fetch ()
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Gets all information about a given object.
Is a variation of find(), see below.

Input: 
1. URI or bNode
2. PolicyURI 

Output:

1. QueryID
2. All known triples about the resource which fullfill the policy


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2. find()
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Gets all triples which fullfil the given pattern.

Input: 
1. Pattern
2. PolicyURI 

Output:  
1. QueryID
2. All known triples which fullfill the pattern and the policy


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3. explain ()
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Explains why a given triple was selected.

Input: 
1. Triple
2. QueryID 

Output: 
1. Explanation Graph using the EXPL Vocabulary


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4. deleteQueryFromCache()
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Deletes the query from the query/explanation cache in order to free resources.

Input: 
1. QueryID 

Output: 
1. true/false