fact: Fixpoint comb_aux l r acc : list (state * state):= match l,r with |x::l,y::r => comb_aux l r ((x,y)::acc) | _,_ => acc end.
imports: ATBR(Common) ATBR(Classes) ATBR(Graph) ATBR(Monoid) ATBR(SemiLattice) ATBR(SemiRing) ATBR(KleeneAlgebra) ATBR(MxGraph) ATBR(MxSemiLattice) ATBR(MxSemiRing) ATBR(MxKleeneAlgebra) ATBR(DKA_Definitions) ATBR(DKA_StateSetSets) ATBR(Utils_WF) Coq(Relations) Coq(List)