(VAR x xs y ys zs )
(STRATEGY INNERMOST)
(RULES 
        isEmpty(nil) -> true
        isEmpty(cons(x,xs)) -> false
        last(cons(x,nil)) -> x
        last(cons(x,cons(y,ys))) -> last(cons(y,ys))
        dropLast(nil) -> nil
        dropLast(cons(x,nil)) -> nil
        dropLast(cons(x,cons(y,ys))) -> cons(x,dropLast(cons(y,ys)))
        append(nil,ys) -> ys
        append(cons(x,xs),ys) -> cons(x,append(xs,ys))
        reverse(xs) -> rev(xs,nil)
        rev(xs,ys) -> if(isEmpty(xs),dropLast(xs),append(ys,last(xs)),ys)
        if(true,xs,ys,zs) -> zs
        if(false,xs,ys,zs) -> rev(xs,ys)
        
)