definition of "testability"?

Regarding the WCAG2.0 conformance proposal [1], do we want to have a definition
for "testability/testable" included in the Glossary?  If so, a possible 
candidate
might be the definition of "testability" found in the Quality Assurance 
Specification
Guidelines [2], as in "testability - a proposition is testable if there is 
such a
  procedure that assesses the truth-value of a proposition with a high 
confidence level."

Thanks and best wishes
Tim Boland NIST

PS - "high confidence level" is used at the end of that paragraph, so that 
mention may
be enough..  Apologies if there already is a definition of "testability" in 
place..



[1]: http://www.w3.org/WAI/GL/2006/11/conformance-revs.html
[2]: http://www.w3.org/TR/qaframe-spec/#glossary