I'm using this code to show that one element of the equation is greater than zero and the second element is less than zero.
\begin{align}
\overset{+}{\pi_{i}} + \overset{-}{w_{g}(S)} > 0
\end{align}
But the alignment of the plus and minus signs are uneven. The minus sign is quite a bit higher than the plus sign. I appreciate help getting the two at the same vertical placement.
the most compact approach to this is to add \mathstrut:
\begin{align}
\overset{+}{\mathstrut\pi_{i}} + \overset{-}{w_{g}(S)} > 0
\end{align}
explanation:
the \overset adjustment is based on the tallest element in the expressions, namely the parentheses around the S.
\mathstrut is defined as {\vphantom(}.
a lot of comments contributed to this. mico's the one who finally came up with \mathstrut.
\overset{+}{\vphantom{S}\pi_{i}} + \overset{-}{w_{g}(S)} > 0– Gonzalo Medina Apr 09 '13 at 16:06\overset{+}{\vphantom{(S)}\pi_{i}}including the parentheses around theS. the difference isn't great, but if you set the two of them closely side by side, with no intervening plus, it's visible. – barbara beeton Apr 09 '13 at 16:15\overset{+}{\vphantom{(}\pi_{i}}or -- prettier still --\overset{+}{\mathstrut\pi_{i}}(because we have\def\mathstrut{\vphantom(}). See also http://tex.stackexchange.com/a/41192/5001. – Mico Apr 09 '13 at 16:26\vphantom{(}and save a couple of keystrokes. – David Carlisle Apr 09 '13 at 16:27