One of the required properties of a probability distribution function for a discrete random variable X is that 
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Definitions:
Haunting Nightmares
Vivid, disturbing dreams that evoke fear and anxiety, often recurring in nature.
Social Withdrawal
The avoidance of social interactions and situations, often due to fear, anxiety, or discomfort.
PTSD
Post-Traumatic Stress Disorder, a mental health condition triggered by experiencing or witnessing a traumatic event.
Psychological Disorder
A disorder characterized by patterns of thought, feeling, or behavior that are deviant, distressing, and dysfunctional, impacting daily functioning.
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