session "Hoare_gen" in "thys" = "HOL" ++− theories +− Hoare_gen+− +− session "Hoare_tm" in "thys" = "Hoare_gen" ++− theories +− Hoare_tm+− +− session "Hoare_abc" in "thys" = "Hoare_tm" ++− theories+− Hoare_abc+−