... 1.11not be accurate as an approximation to y at the end of a step, the value of y+z, if it could be evaluated accurately, would be a very good approximation,because the statement term - (newy - y) ... METHODS FOR ORDINARY DIFFERENTIAL EQUATIONS and the accuracy that is achieved in the step, should be balanced for overallefficiency. If the cost of each step is approximately constant, this means thatthe ... a jk,wherejand k are the beginning and end of the arc (assuming that all directions are inthe sense of movement away from the root). Finally, for each arc terminatingat a leaf, write down a factor, say...