To determine the calorie content of just the purple lettuce, we need to know the specific calorie contributions of the other ingredients in the salad (beets and carrots) and how they fit into the total of 130 calories per cup.
Since we don't have the specific calorie values for beets and carrots in your salad, we can't calculate the exact calorie count for just the purple lettuce without that information. However, if you can provide the calorie counts for beets and carrots per cup or any additional breakdown, I can help you with the calculations.