question: Given the following triplets constituting a sub-graph, please infer the relationship between "story ending generation" and "sentiment control".
  Triplets: story ending generation - Hyponym-Of - natural language generation; sentence generation - Is-a-Prerequisite-of - natural language generation; natural language generation - Conjunction - natural language understanding; Part-of; Conjunction; Evaluate-for; Is-a-Prerequisite-of; Used-for; Hyponym-Of
  Relationships Types: Compare, Part-of, Conjunction, Evaluate-for, Is-a-Prerequisite-of, Used-for, Hyponym-Of