Exercise 9.3

Suppose a knowledge base contains just one sentence, $\exists\,x\ {AsHighAs}(x,{Everest})$. Which of the following are legitimate results of applying Existential Instantiation?

  1. ${AsHighAs}({Everest},{Everest})$.

  2. ${AsHighAs}({Kilimanjaro},{Everest})$.

  3. ${AsHighAs}({Kilimanjaro},{Everest}) \land {AsHighAs}({BenNevis},{Everest})$
    (after two applications).

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