code: function Proxied(stream) {
        var rest;
  
        return inherit(stream, {
          original: function() { return stream; },
          rest: function() { 
            return rest ? rest : Proxied(stream.rest()) }
        });
      }
docs: Foreign Rule Invocation
  =======================
  Allow to borrow the input stream for foreign rule invocation
  the stream is proxied to not fall back on old memoization entires