The YABBY gene family was identified recently by homology to CRABS CLAW, a gene involved in carpel and nectary development in Arabidopsis. Several of the transcription factors encoded by the YABBY genes appear to have conserved roles in specifying abaxial cell fate in leaves, floral organs and ovules.

We present the Hyper system that implements a new approach to knowledge compilation, where function-free rst-order acyclic Horn theories are transformed to propositional logic. The compilation method integrates techniques from deductive databases (relevance reasoning) and theory transformation via unfold/fold transformations, to obtain a compact propositional representation. The transformed the...