Black Stool After Drinking

Update just to upload a photo jam that illustrates that, ultimately, leads to stubbornness somewhere (¿?). xDDD Neee, is that today I have started with Algebra and although the exercise had to solve in another way (and already had shown), I got my saints ovaries to solve based on properties of subsets ...

xDD Anyway, this experience has helped me to be able (now) to implement all the properties whores with eyes closed (and even I can not tell what they're called!), and demonstrate whatever to be demonstrated. Ea.