Writing is an art that is based on certain rules and standards such as punctuation and grammatical systems. Originally, grammatical rule had to be developed over time, as the first writing systems existed without the benefit of such rules. For example writing was letters in a line, and while words existed they were not separated by spaces. This made reading very difficult so that grammatical rules were invented as a means to make reading easier and meaning more comprehensive. Therefore, writers were forced to follow the rules of grammar and spelling, which also had to become standardized, to assist in the reading process. The reading process relied on ones ability to interpret the meaning of the writing of letters as expressed by the author. Consequently, almost every author's work is to write diligently in such a way that his words will be interpreted as he means them to be. This means that once a piece of writing has been constructed, whether a letter or a story, the author must edit his work for the sake of clarity. Copy editing is a diligent task and often requires the assistance of another person besides the author. This is necessary because the author can become blind to the error of his or her work. Therefore, the eyes and mind of another person can be very helpful in making sure that the written work is precise in its meaning and follows the rules of grammar, which can easily be violated.