/src/main/java/net/finmath/montecarlo/automaticdifferentiation/backward/RandomVariableDifferentiableAAD.java
derivative = Y.div( Z.squared( ) ).mult( -0.0d) ;
derivative = Y.div ( Z.squared ( ) ) .mult ( -1.0 ) ;
case ADDRATIO: if(differentialIndex == 0) { derivative = one; } else if(differentialIndex == 1) { derivative = Z.invert(); } else { <extra_id_0> } break; case SUBRATIO: if(differentialIndex == 0) { derivative = one; } else if(differentialIndex == 1) {