model {
   X ~ dpois(lambda);
   lambda <- ls + lB
   ls <- r * T 
   # r ~ dexp(0.00001)
   r ~ dgamma(1, 0.00001)  # gamma, ma esattamente dexp(0.00001)
   lB <- rB * T
   # prior normale su rB (ovviamente non funziona se sigmaB/ErB e' grande 
   # rB ~ dnorm(ErB, tauB)
   # tauB <- 1/(sigmaB*sigmaB)
   # prior gamma su rB 
   rB ~ dgamma(cGamma, rGamma)
   cGamma <- ErB*ErB/(sigmaB*sigmaB)
   rGamma <- ErB/(sigmaB*sigmaB)
}