The term 'Having Studied' can be expressed as 'UPON' in four letters. This phrase is often used to describe a situation in which someone has completed a course of study or has gained knowledge through research and experience. It is commonly used to refer to someone who has studied a particular subject or field of study, such as a degree or certification. It can also be used to describe someone who has studied a particular skill or craft. In either case, the phrase implies that the person has acquired knowledge or expertise in a particular area.