Premise: Dual-role transvestism is the formal diagnosis used by psychologists and physicians to describe people who wear clothes of the opposite sex to experience being the opposite sex temporarily, but don't have a sexual motive or want gender reassignment surgery. The International Classification of Diseases (ICD-10) list three diagnostic criteria for "Dual-role transvestism" (F64.1):
Hypothesis: Dual-role transvestism is what Tom has.