Very Urgent Scheme/ Prolog task

Btree task There is no word document that outlines the instructions. This assignment is the same as the BTree assignment in Java but must be done in Scheme compiled in DrRacket. I am not allowed to use any built in functions in Racket, rather I am suppose to write a function that finds a value in a BST recursively only using "car" , "cadr" and "display". How I was thinking of going through this approach is to define three functions that does the following parse a list inside a leaf node, parse a list inside a rootnode and check if a node is a rootnode or a leafnode. Here is how a sample tree is defined in Scheme (define tree'("R" 100 999 ( ( "R" 100 199(( "L" (120 140 160 180)))) ( "R" 100 199(( "L" (220 240 260 280)))) ) ) )