# [Structure and Interpretation of Computer Programs](https://web.mit.edu/alexmv/6.037/sicp.pdf)

## 1.1.1 Expressions
### Simple
```lisp
486 ;486  
```
### Combining Expressions - _Combinations_
2 numbers
```lisp
; the * is the operator and the numbers are the operands - in this case 25 * 25
(* 25 25) ;625
```
multiple numbers
```lisp
(+ 21 35 12 7) ;75

(* 25 4 12) ;1200
```

## 1.1.2 Naming and the Environment