fact: Definition add_rr_helper (xi yi qi zi : FF) := let xql := FImult2 (lower qi) xi in let xqu := FImult2 (upper qi) xi in let yql := FImult2 (Fminus2 (Float2 1 0) (lower qi)) yi in let yqu := FImult2 (Fminus2 (Float2 1 0) (upper qi)) yi in Fle2 (lower zi) (Fplus2 (lower xql) (lower yql)) && Fle2 (lower zi) (Fplus2 (lower xqu) (lower yqu)) && Fle2 (Fplus2 (upper xql) (upper yql)) (upper zi) && Fle2 (Fplus2 (upper xqu) (upper yqu)) (upper zi).
imports: Gappa_common Gappa_pred_bnd