premise: The Second Silesian War was a theatre of the War of the Austrian Succession. The name is used to describe Prussia's war against Austria between 1744 and 1745, fought mainly in Silesia, Bohemia, and Upper Saxony. It was the second in a series of three Silesian Wars fought between Frederick the Great's Prussia and Maria Theresa's Austria.
hypothesis: The Silesian Wars were the only wars fought between Maria Theresa's Austria and Frederick the Great's Prussia. 
reason: The Silesian Wars were a series of wars fought between Austria and Prussia during the time that Maria Theresa and Frederick the Great were the leaders of those two nations. That doesn't exclude there being other conflicts between the two rulers during their reigns. 