→ ([ _ has seen _ ] Carol the report
∧ [ _ will call _ about _ ] Carol you the report)
(Aam ∨ Abm) → (Scr ∧ Lcor)
if
either
A fits
a ən
m or
A fits
b ən
m
then
both
S fits
c ən
r and
L fits
c, o, ən
r
A: [ _ was at _ ]; L: [ _ will call _ about _ ]; S: [ _ has seen _ ]; a: Ann; b: Bill; c: Carol; m: the meeting; o: you; r: the report
When analyzing atomic sentences into predicates and terms, be sure to watch for repetitions of predicates from one atomic sentence to another—such as that of [ _ was at _ ] in this example. Such repetitions are an important part of the logical structure of the sentence.
Since the notation for identity is different from that used for non-logical predicates, you need to watch for atomic sentences that count as equations. These will usually, but not always, be marked by some form of the verb to be but, of course, forms of to be have other uses, too. Consider the following example:
If Tom was told of the nomination, then if he was the winner he wasn’t surprised
Tom was told of the nomination → if Tom was the winner he wasn’t surprised
Tom was told of the nomination
→ (Tom was the winner → Tom wasn’t surprised)
Tom was told of the nomination
→ (Tom was the winner → ¬ Tom was surprised)
[ _ was told of _ ] Tom the nomination
→ (Tom = the winner → ¬ [ _ was surprised] Tom)
Ltn → (t = r → ¬ St)
if
L fits
t ən
n then
if
t is
r then
not
S fits
t
L: [ _ was told of _ ]; S: [ _ was surprised]; t: Tom; n: the nomination
It is fairly safe to assume that a form of to be joining two individual terms indicates an equation, but it is wise to always think about what is being said: an equation is a sentence that says its component individual terms have the same reference value. A use of to be joining noun phrases will indicate an equation only when these noun phrases are individual terms; the conditions under which that is so are discussed in the next subsection. Finally, notice that no identity predicate should appear in the key to the analysis. That is because it is part of the logical vocabulary; as such, it is like the connectives, which also do not appear in keys.