
Lisp Functions for use with TeXmacs

When Common Lisp is initialized under TeXmacs, several new functions and
variables are available to you: 

(make-tm-string TYPE L)		Returns a TeXmacs-formatted string from a Lisp object.
				TYPE may be one of TREE, SCHEME, or COMMAND. TREE generates a
				graphical tree representing L. SCHEME treats L as a Scheme
				expression for the TeXmacs markup, and COMMAND runs L as 
				arbitrary Scheme code within TeXmacs. 

(make-tm-tree X)	   	Returns the TeXmacs symbol tree corresponding to the
				Lisp tree X. 

tm-data-begin	   		The character (ASCII 2) marking the beginning of a 
		 		TeXmacs control sequence

tm-data-end	   		The character (ASCII 5) marking the end of a TeXmacs
		   		control sequence

(tree-ref T A)			References a node in the tree T using the address list A.

(tree-set T A V)		Sets the node (using the address list A) of T to the new value, V.

TREE-REF and TREE-SET use an address list to reference a nested list (tree). For example, if we
have the tree '(+ 3 2 (* 5 6) 7 8) the address list '(1) refers to +, and the address '(4) refers
to (* 5 6). The address is nested, so the address '(4 2) refers to the node containing 5. 
