  as a first indemonstrable. For testing, a suitable mode of an argument can also be used as a stand-in. A mode is syllogistic, if a corresponding argument with the same form is a syllogism (because of that form). However in Stoic logic there are no five modes that can be used as inference schemata that represent the five types of indemonstrables. For example, the following are two of the many modes of fourth indemonstrables: