In 23.5 (“Quantifiers and Scope”), we find the pair:
Everyone is such that, if they are a bassist, then Lars is a bassist
and its FOL translation
[15-FOL:] ∀x(B(x) → B(l)) .
The English-sentence 15 is of course not really something anyone would say in ordinary conversation, outside a philosophy classroom. My students and I found it helpful, in thinking about what the symbolization 15-FOL actually means, to recognize that 15-FOL can be more naturally translated as “Lars is a bassist, if anyone is” or as “If anybody’s a bassist, Lars is.” (I think my students found this especially helpful, because Chapter 23 is an early-enough part of the textbook that students are still struggling to understand what basic FOL sentences are intuitively saying.)
Of course, this isn’t any kind of logical error in the text. I mention this only as a report of what my particular students found helpful in yesterday's discussion of this material. So the thought was that adding a sentence including this more idiomatic/ natural English translation of 15-FOL might be useful to some readers.
Note: Given the wider pedagogical goals of 23.5, I think it's 100% reasonable to keep 15 as it currently is, since its surface form is closer to the FOL sentence that the section wants to discuss. So I'm just suggesting that in the discussion of the FOL sentence, you could mention this other, more 'everyday' English sentence to help the students grasp the intuitive meaning.
In 23.5 (“Quantifiers and Scope”), we find the pair:
and its FOL translation
[15-FOL:] ∀x(B(x) → B(l)) .
The English-sentence 15 is of course not really something anyone would say in ordinary conversation, outside a philosophy classroom. My students and I found it helpful, in thinking about what the symbolization 15-FOL actually means, to recognize that 15-FOL can be more naturally translated as “Lars is a bassist, if anyone is” or as “If anybody’s a bassist, Lars is.” (I think my students found this especially helpful, because Chapter 23 is an early-enough part of the textbook that students are still struggling to understand what basic FOL sentences are intuitively saying.)
Of course, this isn’t any kind of logical error in the text. I mention this only as a report of what my particular students found helpful in yesterday's discussion of this material. So the thought was that adding a sentence including this more idiomatic/ natural English translation of 15-FOL might be useful to some readers.
Note: Given the wider pedagogical goals of 23.5, I think it's 100% reasonable to keep 15 as it currently is, since its surface form is closer to the FOL sentence that the section wants to discuss. So I'm just suggesting that in the discussion of the FOL sentence, you could mention this other, more 'everyday' English sentence to help the students grasp the intuitive meaning.