f) No burden of proof with regard to negative facts 

In T 2037/18, the board observed that there was no burden of proof ("Darlegungs- und Beweislast") with regard to negative facts to be discharged in substantiating the notice of opposition. Under the rules on the burden of proof applicable in EPC proceedings, each of the parties had to present and prove only the facts in their favour – in line with the principle of "negativa non sunt probanda" (see the summary of this decision in this chapter IV.C.2.2.8 i)).