A proper manual for Llama is in preparation. In the meantime, please refer to the page "getting Llama" for examples of Llama's (fairly simple) syntax.
There is a published paper (1998) describing Llama and its syntax:
LLAMA: an object-oriented system for log multiplicative models. In COMPSTAT 1998, Proceedings in Computational Statistics (ed. R. Payne & P. Green), 305-310. Heidelberg: Physica-Verlag.
David Firth, 21 August 1998