if let Some(cdr) = self.cdr.as_ref() {
            matches!(cdr.as_ref(), Primitive::List(_))
        } else {
            // We are a list by virtue of resembling the empty list.
            // Technically we have 2 representations of "empty list"
            // - a cdr pointer of None (the pointed empty list)
            // - a ConsCell with both car and cdr set to None (the object empty list)
            true
        }

        // We have 2 ways of representing an "empty list" for Scheme
        // - our cdr is pointed to None
        // - our car and cdr are None (if this is so, *we are the empty list*
        // and should technically not be considered for the "pair?" predicate)
        self.cdr
            .as_ref()
            .is_some_and(|cdr| matches!(cdr.as_ref(), Primitive::List(_)))
            || self.cdr.is_none()