Section ua_com_arrow_def.
Variable axf : Comma G x.
Canonical Structure UA_com_arrow := Build_Com_arrow UA_com_law.
End ua_com_arrow_def.
Canonical Structure UA_Initial := Build_Initial UA_isInitial.
(* un obj initial dans (x|G) est Un UA de x vers G *)
Variable axu : Initial (Comma G x).
Definition Com_diese (a' : A) (f : x --> G a') :=
Mor_com_arrow (MorI axu (Build_Com_ob f)).
Let axu_ob := Initial_ob axu.

Lemma Com_UAlaw2 : UA_law2 (Mor_com_ob axu_ob) Com_diese.