YES
(VAR x y)
(RULES
-(x,s(0())) -> p(x)
fib(s(s(x))) -> +(fib(s(x)),fib(x))
fib(0()) -> s(0())
p(s(x)) -> x
fib(s(0())) -> s(0())
dfib(0()) -> s(0())
dfib(s(0())) -> s(0())
dfib(s(s(x))) -> +(dfib(s(x)),+(dfib(x),dfib(x)))
+(x,s(y)) -> s(+(x,y))
+(x,0()) -> x
-(s(x),s(y)) -> -(x,y)
-(x,0()) -> x
)