Observation Cases	Likelihood Contribution
1. Qi = 0	$\exp (-{\sum }_{j=1}^{m_i}{\mu }_{ij})$
2. Qi = 1, ζi = 1, Δi = 0	$G_{i{m}_i}\exp (-{\sum }_{j=1}^{m_i}({\mu }_{ij}+G_{ij})\}$
3. Qi = 1, ζi = Δi = 1	${\mu }_{i{m}_i}\exp (-{\sum }_{j=1}^{m_i}({\mu }_{ij}+G_{ij})\}$
4. Qi = 1, ζi = 0	$(G_{i{m}_i}+{\mu }_{i{m}_i})\exp (-{\sum }_{j=1}^{m_i}({\mu }_{ij}+G_{ij})\}$