Several sample programs exist that illustrate the use of the Low-level Applications Programming Interface (LAPI). Since LAPI runs only with the User Space communications subsystem, it is installed and runs as part of the Parallel System Support Programs (PSSP).
You can find the LAPI sample programs in the /usr/lpp/ssp/css/samples/lapi directory. In that directory, refer to the file README.LAPI, which contains instructions on how to compile and execute the sample programs.