This book specifies the semantics of the Letlang programming language, as well as the requirements for its implementation.

The key words “MUST”, “MUST NOT”, “REQUIRED”, “SHALL”, “SHALL NOT”, “SHOULD”, “SHOULD NOT”, “RECOMMENDED”, “MAY”, and “OPTIONAL” in those documents are to be interpreted as described in RFC 2119.

Enhancement Proposals

To get an history of changes made to this specification, please consult this page.