| #i #H1i #IH #H2i
elim (drops_ldec_dec L i) [ * #K #W #HLK | -H1i -IH #HnX ]
[ lapply (cnv_inv_lref_pair … H2i … HLK) -H2i #H2W
- lapply (csx_inv_lref_pair … HLK H1i) -H1i #H1W
+ lapply (csx_inv_lref_pair_drops … HLK H1i) -H1i #H1W
elim (cpue_total_csx … H1W) -H1W #X
elim (abst_dec X) [ * | -IH ]
[ #p #V1 #U #H destruct * #n #HWU #_
| #p #I #V1 #T1 #_ #IH #H
elim (cnv_inv_bind … H) -H #HV1 #HT1
elim (IH … HV1) [| /3 width=1 by fpb_fpbg, fpb_fqu, fqu_pair_sn/ ] #V2 #HV12
- elim (IH … HT1) [| /3 width=1 by fpb_fpbg, fpb_fqu, fqu_bind_dx/ ] #T2 #HT12
+ elim (IH … HT1) [| /4 width=1 by fpb_fpbg, fpb_fqu, fqu_bind_dx/ ] #T2 #HT12
/3 width=2 by cpce_bind, ex_intro/
| #I #V1 #T1 #_ #IH #H
elim (cnv_fwd_flat … H) -H #HV1 #HT1