Last day I was writing a proof of a theorem in $\LaTeX$, when I realized that I needed to use a symbol meaning implications for efficiency purposes. It is usual in mathematics that one thing leads to another, and it is also usual that we use $\Rightarrow$ as implication symbol. This way, I looked for this issue in the web and I found that double ampersand (&&) could be used to align, just in the same way that one is used to do it with a single ampersand (&). For example, note the implications in the following equations (along as the alignment at the equal symbol and the alignment at left):
Therefore, I used this piece of code in order to get things done.
&& x + 2 &= 4 + 6 \\
\Rightarrow && x &= 4 + 6 - 2 \\
\Rightarrow && x &= 10 - 2 \\
\Rightarrow && x &= 8