As used in this Code:
1. A "presumption" means a rule of procedure that when a basic fact exists the existence of another fact must be assumed, whether or not the basic fact has any probative value of the existence of the assumed fact;
2. "Basic fact" means the fact or group of facts giving rise to a presumption;
3. "Presumed fact" means the fact which must be assumed; and 4. "Inconsistent presumptions" means the presumed fact of one presumption is inconsistent with the presumed fact of another presumption.