anchor.diff:  			this.data[this.size - 2] = this.data[this.size++];
   		}
   	}
  +
   }
   
  
positive.code: 	void Dup() {
  		if (this.size > 0 && this.size < this.maxSize) {
  			this.data[this.size] = this.data[this.size++ - 1];
  		}
  	}
  
  
negative.code: 
  	/// Removes the top stack item and discards it.
  	///
  	/// ( a b -- a )
  	void Drop() {
  		if (this.size > 0) {
  			this.size--;
  		}
  	}
  
  	/// Removes the top 2 stack items and discards them.
  	///
  	/// ( a b c -- a )
  	void Drop2() {
  		if (this.size > 1) {
  			this.size -= 2;
  		}
  	}
  
  