ConceptFree variableModified just nowProperties 4Hide BooksChapter 5. The untyped/pure lambda-calculus JourneyProgramming Language Theory Statusmastered Tagslambda calculussyntax grammarA variable that is not bound by any enclosing λ\lambdaλ. Contrast with Bound variable. Previous in ConceptsForward chaining search backward chaining searchNext in Concepts Fresh renaming