typedef struct _use* Use;
typedef struct duchain* DuChain;

Node duchain_defn(DuChain chain);

Use duchain_firstUse(DuChain chain);

Use duchain_nextUse(Use use);

Node duchain_useNode(Use use);

int compareByOccurence(DuChain* chain1, DuChain* chain2);

int duchain_getID(DuChain chain);

int duchain_maxDepth(DuChain chain);

int duchain_maxDepth(DuChain chain);

ArrayList duchain_getChains(Block b);

Symbol duchain_symbol(DuChain chain);