model
    {
       smoking ~ dcat(p.smoking[1:2])
       tuberculosis ~ dcat(p.tuberculosis[asia,1:2])
       lung.cancer ~ dcat(p.lung.cancer[smoking,1:2])
       bronchitis ~ dcat(p.bronchitis[smoking,1:2])
       either <- max(tuberculosis,lung.cancer)
       xray ~ dcat(p.xray[either,1:2])
       dyspnoea ~ dcat(p.dyspnoea[either,bronchitis,1:2])
    }