Update README.md

README.md

@@ -68,7 +68,7 @@ The dataset is organized so that each entry represents a single task associated
 - **constraint_name**: (string) Name of the spatial relationship (e.g., "left").
 - **image_url**: (string) URL of the image associated with the task.
 - **objects**: (list) List of objects involved in the scene.
-- **related_task_id**: (string) Identifier of a related task, if any.
+- **related_task_id**: (string) Identifier of a related task. Each positive task has a corresponding negative task.
 - **scene_id**: (string) Identifier for the scene where the task occurs.
 
 ### Example Entry