Canonical Structure FT_c1 := Build_Com_arrow FT_eq1.
(* t'' o q est une fleche de FT_m0 -> FT_i0 dans (x|G)I *)

(* Specifications: *)
Lemma FT_eq2 :
Com_law (axf:=Build_Com_ob (FT_f FT_m0)) (bxg:=Build_Com_ob (FT_f FT_j0))
(FT_t'' o FT_q).