3

I have the following code and I dont know how to align the two horizontal \Longleftrightarrows vertically higher than they are now. Ideally they need to be only vertically moved a bit up so that one of them is vertically between c_2 and c_1 and the other needs to be between c_3 and c_4.

\begin{align}
a(y)&=1-a(-y)\nonumber\\
&\Uparrow \nonumber\\
m_u=1/m_l \quad\quad\,\, c_2&=c_3 \quad\quad\,\,  \lambda_0=\lambda_1\nonumber\\
t_u=-t_l\Longleftrightarrow c_1&=c_4 \Longleftrightarrow \mu_0=\mu_1 \nonumber\\
&\Updownarrow \nonumber\\
f_1(y)&=f_0(-y)
\end{align}

This is the first time I am asking question here, therefore excuse me if there is something wrong. Thanks in advance.

Gonzalo Medina
  • 505,128
Seyhmus Güngören
  • 319

2 Answers2

3

One option:

enter image description here

The code:

\documentclass{article}
\usepackage{amsmath}

\begin{document}

\begin{align}
a(y)&=1-a(-y)\nonumber\\
&\Uparrow \nonumber\\
m_u=1/m_l \quad\quad\,\, c_2&=c_3 \quad\quad\,\,  \lambda_0=\lambda_1\nonumber\\
t_u=-t_l\raisebox{1.5ex}[0pt][0pt]{${}\Longleftrightarrow{}$} c_1&=c_4 \raisebox{1.5ex}[0pt][0pt]{${}\Longleftrightarrow{}$} \mu_0=\mu_1 \nonumber\\
&\Updownarrow \nonumber\\
f_1(y)&=f_0(-y)
\end{align}

\end{document}

Or, with aligned, for vertically centered tag:

\documentclass{article}
\usepackage{amsmath}

\begin{document}

\begin{equation}
\begin{aligned}
a(y)&=1-a(-y) \\
&\Uparrow  \\
m_u=1/m_l \quad\quad\,\, c_2&=c_3 \quad\quad\,\,  \lambda_0=\lambda_1 \\
t_u=-t_l\raisebox{1.5ex}[0pt][0pt]{${}\Longleftrightarrow{}$} c_1&=c_4 \raisebox{1.5ex}[0pt][0pt]{${}\Longleftrightarrow{}$} \mu_0=\mu_1 \\
&\Updownarrow \\
f_1(y)&=f_0(-y)
\end{aligned}
\end{equation}

\end{document}

enter image description here

Gonzalo Medina
  • 505,128
2

A diagram with tikz-cd seems a good choice; the only trick is setting the upper and lower items in a zero width box.

\documentclass{article}
\usepackage{amsmath,tikz-cd}

\begin{document}

\begin{equation}
\begin{tikzcd}[row sep=1.2em,column sep=1.5em]
& \makebox[0pt]{$a(y)=1-a(-y)$} \\
\begin{gathered}
m_u=1/m_l\\
t_u=-t_l
\end{gathered}
\arrow[r,Leftrightarrow]
&
\begin{gathered}
c_2=c_3\\
c_1=c_4
\end{gathered}
\arrow[u,Rightarrow]
\arrow[r,Leftrightarrow]
\arrow[d,Leftrightarrow]
&
\begin{gathered}
\lambda_0=\lambda_1\\
\mu_0=\mu_1
\end{gathered}
\\
& \makebox[0pt]{$f_1(y)=f_0(-y)$}
\end{tikzcd}
\end{equation}

\end{document}

enter image description here

Braces around the conditions can be added with \left\{...\right\}:

\documentclass{article}
\usepackage{amsmath,tikz-cd}

\begin{document}

\begin{equation}
\begin{tikzcd}[row sep=1.2em,column sep=1.5em]
& \makebox[0pt]{$a(y)=1-a(-y)$} \\
\left\{\begin{gathered}
m_u=1/m_l\\
t_u=-t_l
\end{gathered}\right\}
\arrow[r,Leftrightarrow]
&
\begin{gathered}
c_2=c_3\\
c_1=c_4
\end{gathered}
\arrow[u,Rightarrow]
\arrow[r,Leftrightarrow]
\arrow[d,Leftrightarrow]
&
\left\{\begin{gathered}
\lambda_0=\lambda_1\\
\mu_0=\mu_1
\end{gathered}\right\}
\\
& \makebox[0pt]{$f_1(y)=f_0(-y)$}
\end{tikzcd}
\end{equation}

\end{document}

enter image description here

egreg
  • 1,121,712