The identity matrix is the matrix for which a_ij = 1 when i = j, and 0 everywhere else. For example, in three dimensions, I = [[1 0 0 ; 0 1 0 ; 0 0 1]]. Here is a column vector: [[0 1 0]]'. x \mapsto y 1/3 %% note: you can still use normal LaTeX in an easylatex file! for example: \begin{eqnarray*} a + b &=& c \\ a &=& c - b \\ \begin{array}{ll} 1 & 2 \\ 3 & 4 \end{array} \end{eqnarray*} Here are some equations which easylatex will automatically align: 1 + 1 = 2 1 = 2 - 1 0 = 2 - 2 For easylatex to deal with a series of naked equations, like in the last three lines, there must be either an empty line, or the end of the file, both before and after the equations. So, the following lines WON'T be automatically aligned: 1 + 1 = 2 1 = 2 - 1 0 = 2 - 2