1\ProvidesPackage{mymath} 2 3\usepackage{euler} 4\usepackage{amssymb} 5\usepackage{amsmath} 6\usepackage{bbm} 7 8\newcommand{\matTT}[9]{ 9\[ 10\left|\begin{array}{ccc} 11 #1 & #2 & #3\\ 12 #4 & #5 & #6\\ 13 #7 & #8 & #9 14\end{array}\right| 15\] 16} 17 18\newcommand{\fork}[4]{ 19 \left\{ 20 \begin{array}{l l} 21 #1 & \mbox{#2}\\ 22 #3 & \mbox{#4}\\ 23 \end{array} \right.} 24\newcommand{\forkthree}[6]{ 25 \left\{ 26 \begin{array}{l l} 27 #1 & \mbox{#2}\\ 28 #3 & \mbox{#4}\\ 29 #5 & \mbox{#6}\\ 30 \end{array} \right.} 31 32\newcommand{\vecthree}[3]{ 33\begin{bmatrix} 34 #1\\ 35 #2\\ 36 #3 37\end{bmatrix} 38} 39 40\newcommand{\vecthreethree}[9]{ 41\begin{bmatrix} 42 #1 & #2 & #3\\ 43 #4 & #5 & #6\\ 44 #7 & #8 & #9 45\end{bmatrix} 46} 47