Accessing Proof Obligations
File Types
For each machine and each context there exists one of each of the following roots:
- IPSRoot: This root contains the statuses (IPSStatus) of the proof obligations. It is contained in a file with the extension .bps.
- IPORoot: This root contains the sequents (IPOSequent) of the proof obligations. It is contained in a file with the extension .bpo.
The Connection between different root types
An IPSRoot, an IPORootand an IMachineRoot or IContextRoot are connected through the name. For example machine m0 has IMachineRoot that is in file m0.bum, IPSRoot in m0.bps and IPORoot in m0.bpo. If one has any of these roots, one get the others though the functions getMachineRoot(), getContextRoot(), getPSRoot() and getPORoot().
Accessing the sequents of an IPORoot
- All sequents of root:
IPOSequent[] sequents = root.getSequents() - A specific sequent (e.g. INITIALISATION/inv1/INV) of root:
IPOSequent sequent = root.getSequent("INITIALISATION/inv1/INV")
Accessing the statuses of an IPSRoot
- All statuses of root:
IPSStatus[] statuses = root.getStatuses() - A specific status (e.g. INITIALISATION/inv1/INV) of root:
IPSStatus status = root.getStatus("INITIALISATION/inv1/INV")
Finding the corresponding status to a given sequent
- 1. Find the IPORoot that contains sequent:
IPORoot poRoot = sequent.getParent; - 2. Find the matching IPSRoot:
IPSRoot psRoot = poRoot.getPSRoot(); - 3. Find the machting status:
IPSStatus status = psRoot.getStatus(sequent.getElementName);
Finding the corresponding sequent to a given status
Use the function getPOSequent() in IPSStatus.
Accessing the proof obligations of a given machine or context
- 1. Find the machting IPORoot for machine (IMachineRoot):
IPORoot poRoot = machine.getPORoot(); - 2. Get all sequents: Accessing the sequents of an IPORoot
- 1. Find the machting IPSFile for machine:
IPSFile psFile = machine.getPSFile(); - 3. For each sequent access the status with the same name in the IPSRoot: Accessing the statuses of an IPSRoot
The sources of a proof obligations
The sources of a proof obligations describe where that proof obligation comes from (e.g. Invariants, Events).
They can be accessed from the IPOSequent: IPOSource[] sources = sequents[i].getSources();
An IPOSource can be an instance of an element like IInvariant, ITheorem etc or it can be an IAction, IWitness or IGuard.
Finding all the proof obligations for a given Invariant
It is not possible to directly find the proof obligations for a given invariant or any other element. Instead check if the sources of the proof obligations contain the invariant.
