Query: Elements affected by a given activity.Purpose: Returns the elements that are sources of basic m-flow-lines in the input liststm_r_mx_source_of_ bm (stm_list in_list,
int *status);
Query: Elements affected by a given activity.Purpose: Returns the elements that are targets of basic m-flow-lines in the input liststm_r_mx_target_of_ bm (stm_list in_list,
int *status);