Section contents.
Variables (m: Monoid) (ms: m -> nat).
About MonoidMonadTrans.M .
Definition monoid_expec {A: Set}:
MonoidMonadTrans.M m ne_tree_monad.ext A -> R
:= expec (ms ∘ (fst (B:=_:Set))).
Hypothesis mh: monoidHomo m NatAddMonoid ms.
Definition monoid_expec_sum (T U: Set)
(g: T -> MonoidMonadTrans.M m ne_tree_monad.ext U): list T -> R
:= Rsum ∘ map (monoid_expec ∘ g).
Proof with auto.
unfold monoid_expec_sum.
intros.
intro.
unfold compose.
f_equal.
apply map_ext.
intro.
f_equal.
apply H.
Qed.
Proof with auto.
unfold monoid_expec, monoid_expec_sum.
intros.
rewrite expec_Node.
rewrite ne_list.map_map.
unfold Ravg.
rewrite ne_list.map_length.
unfold monoid_expec.
rewrite ne_list.plain_map...
Qed.
Proof with auto.
intros.
simpl.
unfold monoid_expec.
unfold expec, compose.
simpl.
rewrite (monoidHomo_zero mh)...
Qed.
Proof with auto.
intros.
rewrite monoid_expec_bind_leaf.
unfold monoid_expec.
rewrite (@expec_ext _ (ms ∘ monoid_mult m (fst n) ∘ fst (A:=m) (B:=Y)) (plus (ms (fst n)) ∘ ms ∘ fst)).
rewrite <- comp_ass.
rewrite (ext_eq_rw (expec_plus_c (ms ∘ fst (A:=m) (B:=Y)) (ms (fst n)))).
reflexivity.
intro.
repeat rewrite comp_apply.
apply (monoidHomo_mult mh).
Qed.
Proof with auto with real.
intros.
rewrite H.
rewrite monoid_expec_bind_leaf_plus.
unfold monoid_expec.
rewrite expec_Leaf.
reflexivity.
Qed.
Hint Resolve ne_tree.In_head.
Proof with auto with real.
revert f.
induction f.
rewrite (@monoid_expec_bind_det _ n)...
unfold ne_tree_monad.deterministic...
unfold monoid_expec in *.
rewrite MonoidMonadTrans.bind_toLower in *.
rewrite ne_tree_monad.bind_Node_one.
repeat rewrite expec_Node_one.
intros.
rewrite IHf...
unfold monoid_expec in *.
rewrite MonoidMonadTrans.bind_toLower in *.
rewrite expec_Node_cons.
rewrite expec_bind_cons.
intros.
rewrite IHf...
rewrite IHf0.
simpl ne_tree.head.
repeat rewrite S_INR.
rewrite (gc (ne_tree.head (ne_list.head l)) (ne_tree.head f))...
simpl.
unfold ne_tree_monad.C.
field...
apply ne_tree.InNode. apply ne_tree.InTail.
destruct l...
intros.
inversion_clear H. inversion_clear H0.
apply gc...
Qed.

Lemma monoid_expec_map_fst_monoid_mult (A: Set) (g: m) (t: MonoidMonadTrans.M m ne_tree_monad.ext A):
monoid_expec (ne_tree.map (map_fst (monoid_mult m g)) t) =
INR (ms g) + monoid_expec t.