DEFINITION clt_wf__q_ind()
TYPE =
       P:CProp
         .n:nat.(λP0:CProp.λn0:nat.c:C.(eq nat (cweight c) n0)(P0 c) P n)
           c:C.(P c)
BODY =
       we must prove 
             P:CProp
               .n:nat.(λP0:CProp.λn0:nat.c:C.(eq nat (cweight c) n0)(P0 c) P n)
                 c:C.(P c)
       or equivalently 
             P:CProp
               .(n:nat.c:C.(eq nat (cweight c) n)(P c))c:C.(P c)
        assume PCProp
        suppose Hn:nat.c:C.(eq nat (cweight c) n)(P c)
        assume cC
          by (refl_equal . .)
          we proved eq nat (cweight c) (cweight c)
          by (H . . previous)
          we proved P c
       we proved 
          P:CProp
            .(n:nat.c:C.(eq nat (cweight c) n)(P c))c:C.(P c)
       that is equivalent to 
          P:CProp
            .n:nat.(λP0:CProp.λn0:nat.c:C.(eq nat (cweight c) n0)(P0 c) P n)
              c:C.(P c)