Consider a vocabulary with the following symbols:
${Occupation}(p,o)$ : Predicate. Person$p$ has occupation$o$ .
${Customer}(p1,p2)$ : Predicate. Person$p1$ is a customer of person$p2$ .
${Boss}(p1,p2)$ : Predicate. Person$p1$ is a boss of person$p2$ .
${Doctor}$ , $ {Surgeon}$, $ {Lawyer}$, $ {Actor}$: Constants denoting occupations.
${Emily}$ , $ {Joe}$: Constants denoting people.
Use these symbols to write the following assertions in first-order
logic:
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Emily is either a surgeon or a lawyer.
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Joe is an actor, but he also holds another job.
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All surgeons are doctors.
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Joe does not have a lawyer (i.e., is not a customer of any lawyer).
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Emily has a boss who is a lawyer.
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There exists a lawyer all of whose customers are doctors.
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Every surgeon has a lawyer.