The safety requirements of a safety-related function comprise the functional safety requirement (what the function does to control the hazard) and the safety integrity requirement (the confidence with which it does it), derived by the risk assessment of EN 50126-2 from the hazards, the tolerable hazard rate and the system architecture; the requirements are expressed so that the design can be verified against them and the safety case can demonstrate them.
The graph holds this control, the 0 it maps to, and the evidence behind each claim, over MCP and REST.