Section PlusWf.
Variable X: Set.
Variable S: relation X.
Variable TX: relation X.
Hypothesis HS: diagram TX S (star TX) (plus S).
Hypothesis Hwf: well_founded (trans S).
Let Hpwf: well_founded (trans (plus S)) := plus_wf Hwf.
Variable TX': relation X.
Hypothesis HS': diagram TX' S (comp (star TX) TX') (plus S).
Variable Y: Type.
Variables R R': relation2 X Y.
Variable TY TY': relation Y.
Hypothesis HR: diagram TX R (star TY) (comp (star S) R).
Hypothesis HR': diagram TX' R (comp (star TY) TY') (comp (star S) R').

(** Proposition 4.4 *)
Theorem diagram_plus_wf_2: diagram (comp (star TX) TX') (comp (star S) R) (comp (star TY) TY') (comp (star S) R').