Slightly Ambiguous Logical Formula in Section 1.2
In the definition of the unique existential quantifier, the logical formula for proving uniqueness has some ambiguity with the mix of a conjunction and an implication. While it is likely clear that the intended interpretation is (p(a) \wedge p(b)) \Rightarrow a = b
from the context given two paragraphs prior, the ambiguity should probably not exist anyway, as there have been no definitions of operator precedence leading up to this point in the book (as far as I can tell).
Probably nothing to cry home about but I figured it would be nice to let you know.