I was wondering if there is a way to change, case's symbol(curly brace) to two arrows pointing up/left and down/left.
\documentclass[a4paper,11pt]{article}
\usepackage{kerkis}
\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{amsfonts}
\usepackage{wasysym}
\usepackage{amsthm}
\usepackage{tikz}
\begin{document}
\begin{align}
\mathbf{\nabla}\times \mathbf{E}=&0\;\begin{cases}\mathbf{E}=-\mathbf{\nabla}\Phi \\ \hat{\eta}\times (\mathbf{E_2}-\mathbf{E_1})=0\mbox{(continiuty)}\end{cases}\\
1+1=&2
\end{align}
%TikZ code "illustrating" the new "brace"
\begin{tikzpicture}
\draw[->] (0,0) -- (1,1);
\draw[->] (0,0) -- (1,-1);
\end{tikzpicture}
\end{document}
Best Answer
Firstly here is a multiarrowed version:
This is obtained by making a
matrix of math nodes
like construction intikz
to build a cases like setup and then drawing the arrows. The syntax requires\&
instead of&
and\\
at the end of each line, because of the way thematrix
construction is set-up intikz
and becuase of interaction with theamsmath
package.Secondly, here is how one replaces the
cases
bracket with another delimiter directly in thecases
environment:This acheived by redefining the
cases
environment to take an optional argument and putting that in the code at the place where\lbrace
was hard coded.Using a
tikz
picture for such a brace in this version is problematic. For a start one needs a construction that can be resized via\left
. Furthermore in your request, you have arrows pointing to each row and that is hard to control. Hence, the multiarrowed code above is probably more what you want.