(VAR x y z )
(STRATEGY INNERMOST)
(RULES 
        rev(nil) -> nil
        rev(.(x,y)) -> ++(rev(y),.(x,nil))
        car(.(x,y)) -> x
        cdr(.(x,y)) -> y
        null(nil) -> true
        null(.(x,y)) -> false
        ++(nil,y) -> y
        ++(.(x,y),z) -> .(x,++(y,z))
        
)