We are assuming that the predicate is ambiguous in the discourse contexts since it can be ambiguously interpreted as either the predicate or as the predicate in some knowledge base. In the third question the predicate is disambiguated for context c6. This will allow us to prove that the GE bid on the FX22 engine is $4M including spare parts. Note that we will have to state the above in the kb context because the discourse contexts are not expressive enough to distinguish between the price including spares and the price excluding spares (which in fact was the source of ambiguity).
Theorem (kb): ist(c_kb ,price-including-spares(engine(22),$4M))
Proof !kb(kb): By reasoning similar to the first question, we can conclude
From the frame axioms we get
similarly to the frame derivation in the second question. Now the theorem follows from the above formulas.
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