Hello World with Clojure and LightTable IDE

Open lighttable and also open the lighttable docs, getting started guide.....

hit your Ctrl + Space Bar.

Type insta until you see the choice 'Open a clojure instarepl'

Once you have chosen to Open a clojure instarepl, the Instarepl pops up in lighttable

then type (+ 3 4)

And 7 pops up as the answer if everything is working correctly.

We are used to seeing 3 + 4 = 7, which is called infix notation. However, clojure operates with prefix notation, which is (+ 3 4) = 7. This is also known as polish notation. Reverse polish notation is known as postfix notation and would be (3 4 +) = 7.