This is an area Reg Braithwaite (AKA raganwald) has explored quite well:
http://github.com/raganwald/homoiconic/blob/master/2008-10-2...
http://github.com/raganwald/homoiconic/blob/master/2008-10-3...
with more links at the bottom of those pages.
Plus, an interesting visual guide to Smullyan's birds:
http://www.cs.virginia.edu/~cs655/readings/mockingbird.html
This is an area Reg Braithwaite (AKA raganwald) has explored quite well:
http://github.com/raganwald/homoiconic/blob/master/2008-10-2...
http://github.com/raganwald/homoiconic/blob/master/2008-10-3...
with more links at the bottom of those pages.
Plus, an interesting visual guide to Smullyan's birds:
http://www.cs.virginia.edu/~cs655/readings/mockingbird.html