Found some information on the actual notation for the book. The extra () fit the notation of the system from Gensler's book apparently. There doesn't appear to

Found some information on the actual notation for the book. The extra () fit the notation of the system from Gensler's book apparently. There doesn't appear to be a precedence order for the connectives, except that unary not (~) doesn't need the parens, ~P and P can both standalone. The language he uses requires the extra parentheses whenever using any of v, ^, ->, or == (and, or, implication, equivalence/iff). This is probably a reasonable thing in context because it means the expressions can be cleanly combined as written and probably avoids confusion for students. They don't have to learn a precedence order. So if a student ever arrives at these pair of statements: (P v Q) R And they use and introduction they'll get: ((P v Q) ^ R) No ambiguity, just combine the two as written and wrap in parens. So I'll retract my previous feedback.