Interface of the R-tree in order to work with postgresql

Hi everybody!<br />I'm Jorge from Peru South America, and this is my first post<br /><br />I want to know how can I add
anew spatial access method into the postgresql (I'm doing research on spatial access methods( reading a lot of papers
andprogramming a lot too ) but also I want to know how can I add my new data structure( if someday i get it, of course
=)) in the postgresql, I mean where can i find the .h that describes the interface that a spatial access method, like
theR-tree, must have in order to work with postgresql.<br /><br />I think that to understand how postgresql works with
spatialaccess methods, like the R-tree, I need to find a .h or .c to begin <br />reading the code, so can you tell me
whereto start?<br /><br />I hope you can help me<br />regards Jorge