Task: Story Composition
Input (English): Premise: Robby's friend had told him that Santa Claus wasn't real. 
 Initial Context: Horrified, Robby asked his mom. 
 Original Ending: She told him she could prove that Santa Claus was real! Late Christmas Eve, she quietly woke him and brought him downstairs. There, in the parlor, he saw Santa Claus leaving his presents! 
 Counterfactual Context: Robby asked his dad and he said it was true.
Output (English): He told him that he could prove that Santa Claus was real! Late Christmas Eve, he quietly woke him and brought him downstairs. There in the parlor, he saw Santa Claus leaving his presents!