Unfortunately if you were able to do this before, there is no way to do it now. Here is a link to the updated Help Article on all shortcuts in Docs: https://support.google.com/docs/bin/answer.py?hl=en&answer=179738
The best way to do it now is Alt+I to access the menu options and C
++Edit (thanks to anon for pointing out easier way to access menus now++
Made an edit to keyboard inputs above to go directly to the Insert menu, and updated the keyboard shortcut for special chars which was changed.
Answer from OnenOnlyWalter on Stack ExchangeVideos
Unfortunately if you were able to do this before, there is no way to do it now. Here is a link to the updated Help Article on all shortcuts in Docs: https://support.google.com/docs/bin/answer.py?hl=en&answer=179738
The best way to do it now is Alt+I to access the menu options and C
++Edit (thanks to anon for pointing out easier way to access menus now++
Made an edit to keyboard inputs above to go directly to the Insert menu, and updated the keyboard shortcut for special chars which was changed.
You can set up your own auto-substitution. Under Tools | Preferences check the box for "Automatic substitution". Then you can add whatever character combination in the "Replace" column with what it will automatically be replaced with in the "With" column.
So, for instance, you might have (c) automatically replace in your document.
(Mine used to be filled with all kinds of shortcuts—as you can see here—but now is blank. I suppose too many people kept asking why their text kept getting replaced.)
For Apple apps, make a text replacement for it:
https://support.apple.com/kb/PH18439
Other apps like MS Word have their own system for this in their menus.
I found several answers for you here: https://stackoverflow.com/questions/3685146/how-do-you-do-the-therefore-%E2%88%B4-symbol-on-a-mac-or-in-textmate
a google search is all it took.
In the character viewer under math symbols. ∴
If you are trying to insert the therefore symbol into a Word document
Hold down the ALT key and type 8756
In Excel, select insert, then select Symbol.
Then using the pulldown menu by Font, select Symbol
Type character code 92 in decimal.
You can do the same in Word as well.
in the symbol section there fore sign was not there but thanks for ALT+8756 was useful in word and than copy and paste to Excel
As stated in the comments, you get the symbols in mathmode simply by writing them down. Packages like amsmath and amssymb support you.
\documentclass{article}
\usepackage{amsmath}
\usepackage{amssymb}
\newtheorem{theorem}{THEOREM}
\newtheorem{proof}{PROOF}
\begin{document}
\begin{theorem}
If an operator has both Left Identity and
Right Identity then it is \emph{UNIQUE}.
\end{theorem}
\begin{proof}
Let $e_{l}$ is left identity
$\therefore e_{l} * e_{r} \implies e_{r}$
\end{proof}
\end{document}
A somewhat larger version of \therefore may be built as:
\dot{.\hspace{.095in}.}\hspace{.5in}
Comparison traditional and larger version: