Scope note: This symmetric property allows the instances of E2 Temporal Entity with the same E52 Time-Span to be equated. This property is only necessary if the time span is unknown (otherwise the equivalence can be calculated). This property is the same as the "equal" relationship of Allen’s temporal logic (Allen, 1983, pp. 832-843). This property is transitive. Examples: - the destruction of the Villa Justinian Tempus (E6) is equal in time to the death of Maximus Venderus (E69) In First Order Logic: P114(x,y) ⊃ E2(x) P114(x,y) ⊃ E2(y) P114(x,y) ⊃ P114(y,x)