SFPM_ — Clarify conformance statement

From AB review by Pete Rivett, March 17, 2020:
Conformance is very unclear. A few times the spec documents “three supporting capabilities” (e.g. in 9.3.1) but these don’t appear under Conformance. That section 9.3.1 also describes 2 purposes: certification (of software) and synthesis. And 3 further capabilities.
And then the end of 9.3.3. refers to another “interface to the external capabilities”