(1) Elements/BooleanVars should link back to expressions that use them --> Done (2) Need to introduce variables in encoding of functions.... --> Done (3) Some cases can do variable elimination of introduced variables... (4) Might need to indicate what variables we can query about in future? (5) Could simplify output of functions... Maybe several outputs have same effect... Work/Passes: (1) TreeConstruction --- need backwards links... BooleanVar/ElementVar should be able to query all of its uses. Should go all the way up... (2) Naive Encoding Pass --- add an encoding to every Element/Function... (3) Encoder Pass --- implement encodings into constraint objects... (4) Test... Make sure the thing works... Next basic implementation phase: (1) Extend Naive Encoder Pass to test other encodings (2) Build more clever function encodings strategies (e.g., equals, add, etc)... (3) Test Actual research: (1) TreeRewriting --- probably should do Equivalent Subexpression Elimination (Don't have the same expression appear twice, instead simply link to it again). Possibly good to do in TreeConstruction... This could be lower priority as it isn't really essential to make things work. Should also probably be switchable on/off... --> Done (2) Advanced TreeRewriting --- can rewrite functions/predicates to eliminate unused entries or to eliminate effectively identical outputs... e.g., consider a function f() that can output the values 1,3, 5, 7, and its output is only ever compared to 3... We could rewrite the values 1, 5, and 7 to be the same value. (3) Advanced Encoding Strategies a) encoding alignment --- making binary index encodings over different sets work together b) Implement K-Map for function encoding (4) Implement search framework --- probably simulated annealing over a population of strategies... search framework should probably be able to turn on/off nearly any optimization we have... (5) Implement backend translation strategies....do optimizations and implement other simplifcation strategies (6) Convert SATCheck to use Constraint Compiler...not sure about order... Started... (7) Profile system.... --------------------------------------------------------------------- To do: (0) Support for saving/loading problem instances... (1) Complete satcheck support (2) Advance tree rewriting... Variable value elimination... (3) Think about undefined semantics... (4) Smart encoding... Variable Graphs.... Split graph into connected components Encoding ideas: * Monotonic increasing index * Matched index (equality) * Bit exposes * Single var * Support arithmetic * Sparse encoding --------------------------------------------------------------------