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

LAU

   Langage a Assignation Unique.  A single assignment language
   for the LAU dataflow machine, Toulouse.

   ["Pipelining, Parallelism and Asynchronism in the LAU System",
   J.C. Syre et al, Proc 1977 Intl Conf Parallel Proc,
   pp. 87-92].