/src/main/java/net/finmath/montecarlo/automaticdifferentiation/backward/RandomVariableDifferentiableAAD.java
derivative = X.mult( Z) ;derivative = one;
derivative = one;
derivative = X.sub(X.getAverage()*(2.0*X.size()-1.0)/X.size()).mult(2.0/X.size()).mult(0.5).div(Math.sqrt(X.getVariance() * X.size())); break; case SVARIANCE: derivative = X.sub(X.getAverage()*(2.0*X.size()-1.0)/X.size()).mult(2.0/(X.size()-1)); break; case ADD: <extra_id_0> break; case SUB: derivative = differentialIndex == 0 ? one : minusOne; break; case MULT: derivative = differentialIndex == 0 ? Y : X;