-In real-time systems with threads, resource locking and
-priority scheduling, one faces the problem of Priority
-Inversion. This problem can make the behaviour of threads
-unpredictable and the resulting bugs can be hard to find. The
-Priority Inheritance Protocol is one solution implemented in many
-systems for solving this problem, but the correctness of this solution
-has never been formally verified in a theorem prover. As already
-pointed out in the literature, the original informal investigation of
-the Property Inheritance Protocol presents a correctness "proof" for
-an incorrect algorithm. In this paper we fix the problem of
-this proof by making all notions precise and implementing a variant of
-a solution proposed earlier. Our formalisation in Isabelle/HOL
-uncovers facts not mentioned in the literature, but also shows how to
-efficiently implement this protocol. Earlier correct implementations
-were criticised as too inefficient. Our formalisation is based on
-Paulson's inductive approach to verifying protocols.
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