[Boost-users] [statechart] orthogonal states in state_machine?

I would like to create a state_machine class that contains some context information that can be written by orthogonal<0> and read by orthogonal<1>. Graphically: _______________ | State Machine | |_______________|______________ | | | StateA1 <------> StateA2 | | - - - - - - - - - - - - - - | | StateB1 <------> StateB2 | |_______________________________| I declare using struct StateA1, StateB1; struct MyStateMachine : sc::state_machine< MyStateMachine, mpl::list > {}; struct StateA1 : sc::simple_state > {}; but get a compile error on line 2 as "orthogonal not a member of MyStateMachine". Do I need to declare one state in MyStateMachine, and make the mpl::list a second template argument to it in order to get what I want? Thanks in advance, Chris