====== Client API ======
Client API is used to communicate with rule engines. API interfaces and classes are located in ''[[http://www.hammurapi.com/products/rules/doc/api/com/hammurapi/reasoning/package-summary.html|com.hammurapi.reasoning]]'' package.
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===== Forward reasoning =====
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The diagram above shows typical steps in working with a forward reasoning session:
  - Obtain a reference to a reasoning session factory. This step is implementation specific and is not covered by the specification. For example, in J2EE environment it can be JNDI lookup and in a standalone application it can be instantiation of a factory class with **new**.
  - Create a reasoning session.
  - Put facts to the session.
  - Execute rules.
  - Retrieve conclusions from the session.
  - Close the session.
===== Backward reasoning =====
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This is a typical backward reasoning scenario:
  - Obtain a reference to a reasoning session factory. This step is implementation specific and is not covered by the specification. For example, in J2EE environment it can be JNDI lookup and in a standalone application it can be instantiation of a factory class with **new**.
  - Create a reasoning session providing an array of input fact sources. These sources can be database queries, files, other backward reasoning sessions, ...
  - Retrieve conclusions of desired type from the session. This operation can be performed multiple times for different or same conclusion types.
  - Close the session.