Hi Mira:

Doug, Johan and I met on Wednesday to discuss the problem
of deciding whether a strategy S1 is a substrategy of strategy S2.

First we tried to solve the problem with intersection of NFAs
and then we realized the the issue is one of embedding one
graph into another graph. A search in Garey and Johnson revealed
that this is called "subgraph homeomorphism". On the web
we found a reference which seems to solve the problem efficiently.
Our discussion is on the web at:

/proj/adaptive/www/design-decisions/traversal-strategies/substrategy

Johan is in charge of writing a technical report on type checking
adaptive programs. 

Motivation: (among others) We need this for APPCs.

-- Karl