Scope note: This property describes the minimum length of time covered by an E52 Time-Span. It allows an E52 Time-Span to be associated with an E54 Dimension representing it’s minimum duration (i.e. it’s inner boundary) independent from the actual beginning and end. Examples: - the time span of the Battle of Issos 333 B.C.E. (E52) had at least duration Battle of Issos minimum duration (E54) has unit (P91) day (E58) has value (P90) 1 (E60) In First Order Logic: P83(x,y) ⊃ E52(x) P83(x,y) ⊃ E54(y)