```Scheme
➜ chapter01 git:(master) ✗ mit-scheme
MIT/GNU Scheme running under OS X
Type `^C' (control-C) followed by `H' to obtain information about interrupts.
Copyright (C) 2014 Massachusetts Institute of Technology
This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
Image saved on Wednesday January 4, 2017 at 8:46:32 AM
Release 9.2 || Microcode 15.3 || Runtime 15.7 || SF 4.41 || LIAR/C 4.118 || Edwin 3.116
1 ]=> (load "circumference.scm")
;Loading "circumference.scm"... done
;Value: circumference
1 ]=> circumference
;Value: 62.8318
```
