9 ). ▁In ▁contrast , ▁the ▁costs ▁for ▁lit ig ating ▁a ▁European ▁pat ent ▁can ▁be ▁much ▁higher ▁(" For ▁example , ▁in ▁Germany ▁the ▁total ▁lit ig ation ▁costs ▁can ▁be ▁as ▁high ▁as ▁€ 2 ▁million ▁with ▁€ 1 0 ▁million ▁at ▁st ake "). ▁An ▁opposition ▁case ▁is ▁reported ▁to ▁take ▁on ▁average ▁three ▁years ▁to ▁be ▁handled ▁by ▁the ▁E PO . ▁ ▁Par allel ▁national ▁proceed ings ▁The ▁" poss ibility ▁of ▁parallel ▁valid ity ▁proceed ings ▁in ▁national ▁courts ▁and ▁in ▁the ▁E PO ▁is ▁inher ent ▁in ▁the ▁legal ▁arrang ements ▁in ▁the ▁E PC ▁under ▁which ▁the ▁E PO ▁was ▁established ". ▁If ▁a ▁third ▁party ▁files ▁an ▁opposition ▁to ▁a ▁European ▁pat ent ▁with ▁the ▁E PO ▁and ▁also , ▁in ▁parallel , ▁initi ates ▁a ▁rev ocation ▁action ▁( also ▁called ▁" null ity ▁action " ▁or ▁" valid ity ▁proceed ings ") ▁against ▁the ▁same ▁pat ent ▁before ▁a ▁national ▁court , ▁the ▁national ▁court ▁( at ▁least ▁in ▁England ) ▁may ▁exercise ▁its ▁dis cret ion ▁to ▁either ▁▁ ▁stay ▁the ▁national ▁proceed ings , ▁in ▁order ▁to ▁wait ▁the ▁outcome ▁of ▁the ▁E PO ▁opposition ▁proceed ings , ▁or ▁ ▁allow ▁the ▁rev ocation ▁proceed ings ▁to ▁go ▁ahead , ▁without ▁waiting ▁the ▁outcome ▁of ▁the ▁E PO ▁proceed ings . ▁ ▁The ▁rules ▁and ▁practice ▁differ ▁from ▁country ▁to ▁country ▁in ▁that ▁respect . ▁" For ▁example , ▁as ▁of ▁ 2 0 0 8 , ▁Belg ium