2986	 Operations on Sparse Relations	 Various computations on relations Boolean matrices or directed graphs such as the computation of precedence relations for a context-free grammar can be done by a practical algorithm that is asymptotically faster than those in common use. For example how to compute operator precedence or Wirth-Weber precedence relations in O n steps is shown as well as how to compute linear precedence functions in O n steps is shown as well as how to compute linear precedence functions in O n steps where n is the size of a grammer. The heart of the algorithms is a general theorem giving sufficient conditions under which an expression whose operands are sparse relations and whose operators are composition transitive closure union and inverse can be computed efficiently. computational complexity sparse relation Boolean matrix directed graph Wirth-Weber precedence relation linear precedence function SLR grammar T-canonical precedence relation
