[MrJohz]

I suspect it's more likely an artifact of how the number is lexed. `-3^2` probably gets lexed into Number(-3), Operator(^), Number(2), which results in the aforementioned precedence issues. The reason for parsing the operator with the number is that it makes it easier to handle the case where you just write a negative number as a literal value into a cell.

Source: I've written an Excel clone before. I don't believe it has the same bug, but if it does, that will be how it's crept in.

EDIT: looking at some of the descriptions of the bug, it seems like it happens when handling variables (i.e. cell references) as well, which makes it seem like a pure precedence issue and not a parsing issue. So I've got no idea, presumably someone simply messed up the precedence order.

[tsimionescu]

It's almost certainly a precedence issue. It's much easier to consider that unary operators have precedence over binary operators, and just learn the precedence rules for each class, rather than a global precedence rule. Plus, there's no conflict with math notation, as there is no exponentiation operator in math.