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