On the BDD/FC Conjecture
  Bounded Derivation Depth property (BDD) and Finite Controllability (FC) are two properties of sets of datalog rules and tuple generating dependencies (known as Datalog +/- programs), which recently attracted some attention. We conjecture that the first of these properties implies the second, and support this conjecture by some evidence proving, among other results, that it holds true for all theories over binary signature. 
Tomasz Gogacz and Jerzy Marcinkowski
cs.DB