press esc or type :q to exit, type :h for help
> 2+5
7

> 2+2*2
6  <-- when typing it should change dynamically, it may be too ambitious though

> (2+2)*2
8

> :h
This is help, it should appear instantly after user presses :h
Type your equation to the terminal and get quick answers

commands:
:h - help - displays this message
:a - about program
:q - exit

> 2+2:h
It should not print equation result here
<display help message here>
It should not remove equation

> 2+2
4