We’ve known about algorithms for millennia, but we’ve only been writing computer programs for a few decades. A big difference between the Euclidean or Eratosthenes age and ours is that since the middle of the twentieth century, we express the algorithms we conceive using formal languages: programming languages. Computer scientists are not the only ones who use formal languages. Optometrists, for example, prescribe eyeglasses using very technical expressions, such as “OD: () 180◦ OS: () 180◦”, in which the parentheses are essential. Many such formal languages have been created throughout history: musical notation, algebraic notation, etc. In particular, such languages have long been used to control machines, such.
