Well-defined

See also

• existenceExistence
  
  There is no universally accepted theory of what the word existence means....
  
• uniqueness
• Defined and undefinedDefined and undefined
  
  In mathematics, defined and undefined are used to explain whether or not expressions have meaningful, sensible output....
  
• Uniqueness quantificationUniqueness quantification
  
  In predicate logic and technical fields that depend on it, uniqueness quantification, or unique existential quantificatio...