The Free On-line Dictionary of Computing (30 December 2018):

Siri

   An object-oriented constraint language using a single
   abstraction mechanism developed by Bruce Horn of CMU in
   1991.  Siri is a conceptual blend of BETA and Bertrand.
   It is similar to Kaleidoscope.

   ["Constraint Patterns as a Basis for Object-Oriented
   Constraint Programming", B. Horn, OOPSLA '92 (Sept 1992)].

   (1994-11-04)