1. An attribute of values which are used exactly once: they are neither duplicated nor destroyed. Such values require no garbage collection, and can safely be updated in place, even if they form part of a data structure.

Linear types are related to the linear logic of J.-Y Girard. They extend Schmidt's notion of single threading, provide an alternative to Hudak and Bloss' update analysis, and offer a practical complement to Lafont and Holmström's elegant linear languages.

['Use-Once' Variables and Linear Objects - Storage Management, Reflection and Multi-Threading, Henry Baker. ].

["Linear types can change the world!", Philip Wadler, "Programming Concepts and Methods", April 1990, eds. M. Broy, C. Jones, pub. North-Holland, IFIP TC2 Working Conference on Programming Concepts and Methods, Sea of Galilee, Israel].