Does anyone know of an online lambda calculator? Or actually I need an online calculator that allows the result to be used in the next calculation. Like the "Ans[wer]" key on some realworld calculators. It allows me to see for myself how for example the Cauchy series "1/Ans + Ans/2" converges. The difference with a sequence like "2*2 Ans" is that know the previous answer have to be used on two places in the equation.