extern	Tree   node();
extern	Tree   tnoop();
extern	Tree   tseq();
extern	Tree	top();
extern	Tree	tunop();
extern	Tree	tconvert();
extern	Tree	tstore();
extern	Tree	teseq();
extern	Tree	tname();
extern	Tree	tconst();
extern	Tree	tconstf();
extern	Tree  tcall();
extern	Tree	tcand();
extern	Tree	tcor();
extern	Tree	tnot();
extern	Tree    trel();
extern	Tree targ();
extern	Tree tifelse();
extern	Tree tfor();
extern	Tree twhile();
extern	Tree tnoargs();