331 Calculator
(type ? for help and . to exit)

>> Enter an expression in infix notation followed by a newline.
Operators include +, -, * and =.  Defined functions include
sqrt, exp and log.  You can assign a variable using the =
operator. Type . to exit.  Syntax errors will terminate the
program, so be careful.

>> 100

>> 2

>> 7

>> 9

>> 0

>> 100

>> 100

>> 200

>> 0

>> 1

>> 1

>> 1

>> -42

>> 42

>> 4

>> 43

>> -41

>> 1

>> 6

>> Exiting 331 calc