Listing 6

const UncertainPtr alpha( uncertain(0.01,1E-4,"alpha") );
const UncertainPtr R_20( uncertain(100.0,1,"R_20") );
UncertainPtr T = uncertain(26,1,"T"); // Measured somehow
UncertainPtr R = R_20*(constant(1) + alpha * (T - constant(20)));
// Averaging
 ...
P = power( accum , R );
print(P);