lsl

from The Free On-line Dictionary of Computing (8 July 2008)

LSL

   1. Larch Shared Language.  An assertion language.  (See
   Larch).

   2. Link and Selector Language.  Graphic query language.  "LSL:
   A Link and Selector Language", D.C. Tsichritzis, Proc Intl
   Conf Management of Data, ACM 1976, pp.123-134.