\lambda (g: G).(\lambda (c: C).(C_ind (\lambda (c0: C).(csubt g c0 c0))
(\lambda (n: nat).(csubt_sort g n)) (\lambda (c0: C).(\lambda (H: (csubt g c0
c0)).(\lambda (k: K).(\lambda (t: T).(csubt_head g c0 c0 H k t))))) c)).
\lambda (g: G).(\lambda (c: C).(C_ind (\lambda (c0: C).(csubt g c0 c0))
(\lambda (n: nat).(csubt_sort g n)) (\lambda (c0: C).(\lambda (H: (csubt g c0
c0)).(\lambda (k: K).(\lambda (t: T).(csubt_head g c0 c0 H k t))))) c)).