Proof
CR_WHNF_convert_hn srt_ecc ecc_sort_dec (beta_delta_rule srt_ecc)
(church_rosser_beta_delta srt_ecc) whnf.

(* Specifications: *)
Theorem ecc_is_subtype_dec : subtype_dec_CTS _ ecc.
apply Build_subtype_dec_CTS.
Theorem ecc_is_subtype_dec : subtype_dec_CTS _ ecc.
apply Build_subtype_dec_CTS.