Pollution in the fashion industry impact on the environment, the natural crop growing fibers also have been contributing to pollution through the form of agriculture. Cotton production requires a large amount of pesticides and water use. Cotton is considered the world's dirtiest crop because it uses 16% of the world's pesticides. Two of the main ingredients in pesticides are nitrates and phosphates. When the pesticides leak into stream systems surrounding the cropland the nitrates and phosphates contribute to water eutrophication. Water eutrophication is an environmental phenomenon that causes a depletion of oxygen when the nutrient overload from pesticides causes a boom in plant growth and
Proofs involving the addition of natural numbers Proofs involving the addition of natural numbers This article contains mathematical proofs for some properties of addition of the natural numbers: the additive identity, commutativity, and associativity. These proofs are used in the article Addition of natural numbers. This article will use the Peano axioms for the definitions of addition of the natural numbers, and the successor function S(a). In particular: For the proof of commutativity, it is useful to define another natural number closely related to the successor function, namely "1". We define 1 to be the successor of 0, in other words, Note that for all natural numbers