Hi all, i defined a transition table with more than 20 transitions. After that the compiler complained that a fusion set is only defined up to 10 elements. So i added the following statement in the file as indicated by the doc. #define BOOST_MPL_CFG_NO_PREPROCESSED_HEADERS #define BOOST_MPL_LIMIT_VECTOR_SIZE 30 //or whatever you need #define BOOST_MPL_LIMIT_MAP_SIZE 30 //or whatever you need However this does not solve the problem, since it is fusion who is complaining. So i added these two statements at the beginning, and this solved the problem. # define FUSION_MAX_SET_SIZE 30 # define FUSION_MAX_VECTOR_SIZE 30 Perhaps we can add this somewhere in the doc. Kind regards , Kim