Should we distinguish the minus sign from the negative sign? In the set $\mathbb{C}$ of complex numbers, the minus sign "-" may be used for following:


*

*As a unary operator $-_u$, given a complex number $a$, $-_ua$ is the unique number (called the negative of a) $c$ such that $a+c=c+a=0$, where $0$ is the additive identity.

*As a binary opeartor $-_b$, given two complex numbers $a$ and $d$, $a-_bd$ is the sum of $a$ and $-_ub$.


Though $-_u$ and $-_b$ are closely related, they are completely different objects in mathematics: $_u$ is considered as a map from $\mathbb{C}$ to $\mathbb{C}$ while $-_b$ is a map from $\mathbb{C}\times\mathbb{C}$ to $\mathbb{C}$. As maps, they have the same codomain but different domains.
In some calculators such as TI nspire, two different keys are used for the two different meanings of $-$. However, in our everyday writing, we seldom differentiate the unary opeartor $-_u$ and $-_b$. Shouldn't we use diffrent symbols for them; after all, though closely related, they are different?
If we do not use different symbols for them, the following simple calculation appears confusing:
\begin{equation*}\begin{array}{c}
\phantom{\times9}-23\\
\underline{-\phantom{9}-15}
\\
\phantom{999}-8
\end{array}\end{equation*}
Also, I find the idea that in the same equation $-1-1=-2$, the first $-$ has different meaning from the second $-$ unsatisfactory.

We do distinguish most of the time, at such a subconscious level that it seems either automatic or unthinking. Heck, we're even capable of resolving meanings that a computer would find contradictory.
Take for instance $$\frac{3}{2} = 1 + \frac{1}{2}.$$ In a cake recipe, you might find something like 
1-1/2 cups light brown sugar

Put that in the context of JavaScript and it could be misunderstood as $$1 - \frac{1}{2} = \frac{1}{2}.$$ But if the author had meant one half rather than three halves, why didn't they just write one half? We understand in the recipe context that the author meant three halves, not one half.
If that's not manly enough an example, try a search for a 1-1/2 socket wrench.
