LEGOL[1]

A query language for temporal databases. Specifically, applications such as legislative rules writing in which the temporal ordering of events and the valid times for objects are important. It was the first relational query language to support temporal queries.

"Application of MP/3 to the Design and Implementation of LEGOL, A Legally Oriented Language", S. H. Mandil et al, International Symposium on Programming, Paris, 1974.

S. Jones, P. Mason and R. Stamper, "LEGOL 2.0: A Relational Specification Language for Complex Rules". Information Systems 4 (4), pp. 293--305, 1979.