In OpenXM, each process may have a hybrid interface; it may accept and execute not only stack machine commands, but also its original command sequences. We call such a process an OX stack machine. Here we introduce OXexpression and SMexpression to express OX messages and SM objects respectively.
A comma `,' may be used to separate elements in an expression. OX_tag is a constant which denotes an OX message tag. SM_tag is a constant which denotes an SM command tag. If a sender AAA or a receiver BBB has to be specified, 'From AAA' or 'To BBB' is written before the OXexpression.
For example the following expression means a request to push a CMO string ``Hello''.
The following expression means a request to execute a local function ``hoge''.