The LarCh ProjeCt develops aids for formal speCifiCations. EaCh LarCh speCifiCation has two Components: an interfaCe Containing prediCates written in the LIL ({LarCh InterfaCe Language}) designed for the target language and a ' trait' Containing assertions about the prediCates written in LSL, the LarCh Shared LanguageCommon to all. ["The LarCh Family of SpeCifiCation Languages", J. Guttag et al, IEEE Trans Soft Eng 2(5):24-365 (Sep 1985)].