Continental Congress. Franklin returned to Philadelphia in 1775. There he served as a delegate to the Continental Congress, where he was instrumental in drafting the Declaration of Independence and the Articles of Confederation to form a new union.
In its simplest form (when r is an integer), the negative binomial distribution models the number of failures x before a specified number of successes is reached in a series of independent, identical trials. Its parameters are the probability of success in a single trial, p, and the number of successes, r. A special case of the negative binomial distribution, when r = 1, is the geometric distribution, which models the number of failures before the first success. More generally, r can take on non-integer values.
Actually, zero is neither a negative or a positive number. The whole idea of positive and negative is defined in terms of zero. Negative numbers are numbers that are smaller than zero, and positive numbers are numbers that are bigger than zero. Since zero isn't bigger or smaller than itself (just like you're not older than yourself, or taller than yourself), zero is neither positive nor negative.