fact: Fixpoint remove e := if contains_one e then match e with | RegExp.plus a b => plus_but_one (remove a) (remove b) | RegExp.dot a b => plus_but_one (remove a) (remove b) | RegExp.star e => e | e => e end else e.
imports: ATBR(Common) ATBR(Classes) ATBR(Graph) ATBR(SemiLattice) ATBR(Monoid) ATBR(SemiRing) ATBR(KleeneAlgebra) ATBR(Model_RegExp) Coq(Bool)