Sentence:  [I]n most cases once the Court has performed its judicial function – as it had been determined by the parties through their Application or Special Agreement and their submissions – and has rendered its judgment on the <WSD>merits</WSD> of the case, a new phrase of functional interaction commences. 
Meaning of the word marked with <WSD> tags:  "Usually in the plural form" '''the merits''': the substantive rightness or wrongness of a legal argument, a lawsuit, etc., as opposed to technical matters such as the admissibility of evidence or points of legal procedure;  the overall good or bad quality, or rightness or wrongness, of some other thing.