(defun Plus (a b) $Num(eval(PNODE(a))->nd.num+eval(PNODE(b))->nd.num)
)
(defun Minus(a b) $Num(eval(PNODE(a))->nd.num-eval(PNODE(b))->nd.num)
)
(defun Uminus( b) $Num(-eval(PNODE(b))->nd.num)
)
(defun Times(a b) $Num(eval(PNODE(a))->nd.num*eval(PNODE(b))->nd.num)
)
(defun Div  (a b) $Num(eval(PNODE(a))->nd.num/eval(PNODE(b))->nd.num)
)
(defun Mod  (a b) $Num(eval(PNODE(a))->nd.num%eval(PNODE(b))->nd.num)
)
(defun If (Cond Then Else) $(ENUM(Cond))?PNODE(Then):PNODE(Else)
)
(defun EqNonStrict (a b) $((PNODE(a)->tag==NUM&&PNODE(b)->tag==NUM)?((PNODE(b)->nd.num==PNODE(a)->nd.num)?Num(1):Num(0)):((PNODE(a)->tag==NIL&&PNODE(b)->tag==NIL)?Num(1):Num(0)))
)
(defun LeqNonStrict (a b) $((PNODE(a)->tag==NUM&&PNODE(b)->tag==NUM)?((PNODE(a)->nd.num<=PNODE(b)->nd.num)?Num(1):Num(0)):Num(0))
)
(defun LtNonStrict (a b) $((PNODE(a)->tag==NUM&&PNODE(b)->tag==NUM)?((PNODE(a)->nd.num<PNODE(b)->nd.num)?Num(1):Num(0)):Num(0))
)
(defun GeqNonStrict (a b) $((PNODE(a)->tag==NUM&&PNODE(b)->tag==NUM)?((PNODE(a)->nd.num>=PNODE(b)->nd.num)?Num(1):Num(0)):Num(0))
)
(defun GtNonStrict (a b) $((PNODE(a)->tag==NUM&&PNODE(b)->tag==NUM)?((PNODE(a)->nd.num>PNODE(b)->nd.num)?Num(1):Num(0)):Num(0))
)
(defun Leq (a b) $LeqNonStrict(eval(PNODE(a)),eval(PNODE(b)))
)
(defun Lt (a b) $LtNonStrict(eval(PNODE(a)),eval(PNODE(b)))
)
(defun Geq (a b) $GeqNonStrict(eval(PNODE(a)),eval(PNODE(b)))
)
(defun Gt (a b) $GtNonStrict(eval(PNODE(a)),eval(PNODE(b)))
)
(defun Eq (a b) $EqNonStrict(eval(PNODE(a)),eval(PNODE(b)))
)
(defun Car (a) $(eval(PNODE(a))->nd.cons.hd)
)
(defun Cdr (a) $(eval(PNODE(a))->nd.cons.tl)
)
---