If an output port on a compound step is not a primary output port, then it will not
      be connected to the last step in the subpipeline. In this test, the pipeline’s
      result output port is not connected, so it receives no documents. It is
      also not declared to accept a sequence, so it must receive exactly one document.
      Consequently, err:XD0007 is raised.
See also [[primary-input-output]][XP] and [[p.output]][XP].
Test ab-connection-003.xml is expected to fail with error code err:XD0007.
<p:declare-step xmlns:err="http://www.w3.org/ns/xproc-error" xmlns:p="http://www.w3.org/ns/xproc" version="3.0">
   <p:output port="result" primary="false">
   <p:identity>
      <p:with-input port="source">
         <t:doc/>
      </p:with-input>
   </p:identity>
</p:declare-step>
Fixed error code expected.
Improve the description of the test.
Some tests changed and new tests
Fix namespace declarations
Creating new tests, extending rng and corrected xproc's test