Suppose a mathematician's calculator has a function that computes the slope and intercept of a line. The requirement in the definition document reads: "the calculator shall accept as input an equation of the form Ax + By + C = 0 and print out the slope and intercept." This system implementation of this requirement is the function line whose syntax is a LINE (A, B, C), where A and B are the coefficients of x and y, and C is a constant in the equation. The result is a printout of D and E, where D is the slope and E the intercept. Rate this requirement as a set of causes and effects, and draw the corresponding cause and effect graph.