(VAR X Y Z )
(RULES 
        sel(0,cons) -> X
        sel(s,cons) -> sel(X,Z)
        dbl1(s) -> s1(s1(dbl1(X)))
        sel1(0,cons) -> X
        sel1(s,cons) -> sel1(X,Z)
        quote(s) -> s1(quote(X))
        dbl(0) -> 0
        dbl(s) -> s
        dbls(nil) -> nil
        dbls(cons) -> cons
        indx(nil) -> nil
        indx(cons) -> cons
        from -> cons
        dbl1(0) -> 01
        quote(0) -> 01
        quote(dbl(X)) -> dbl1(X)
        quote(sel(X,Y)) -> sel1(X,Y)
        
)