/src/main/java/net/finmath/montecarlo/automaticdifferentiation/backward/RandomVariableDifferentiableAAD.java
derivative = differentialIndex == typePriorityDefault ? one : minusOne;
derivative = differentialIndex == 0 ? one : minusOne;
derivative = X.sub(X.getAverage()*(2.0*X.size()-1.0)/X.size()).mult(2.0/(X.size()-1)); break; case ADD: derivative = one; break; case SUB: <extra_id_0> break; case MULT: derivative = differentialIndex == 0 ? Y : X; break; case DIV: derivative = differentialIndex == 0 ? Y.invert() : X.div(Y.squared()).mult(-1);