fix more warnings

theories/algebra/irelations.v

@@ -13,6 +13,7 @@
 
 From Coq Require Import Wf_nat Omega.
 From stdpp Require Export tactics base relations list collections.
+From stdpp Require set.
 
 (** * Definitions *)
 Section definitions.
@@ -979,7 +980,7 @@ Section cofair.
   Lemma co_se_trace_valid {x1} {e: trace R1 x1} {x2} (ST: co_se_trace e x2):
     co_se e (co_se_trace_extract ST).
   Proof.
-    revert x1 e x2 ST; cofix; intros.
+    revert x1 e x2 ST; cofix COFIX; intros.
     destruct ST; subst. 
     unfold co_se_trace_extract.
     rewrite trace_aux_id; simpl.
@@ -1336,7 +1337,7 @@ Section cofair.
   End erasure.
 
   Section block.
-    From stdpp Require Export set.
+    Import stdpp.set.
     Context (flatten: A → B * (nat → set nat)).
     Context (flatten_spec_step:
                ∀ i a a',  R1 i a a' → 

theories/prelude/set_finite_setoid.v

@@ -2,6 +2,8 @@ From Coq.ssr Require Export ssreflect.
 From fri.prelude Require Export list compact.
 From stdpp Require Export prelude mapset.
 From stdpp Require Export set natmap fin_collections collections fin_maps.
+From stdpp Require set.
+From Coq Require Classical_Pred_Type.
 
 Lemma subseteq_union_decompose:
   ∀ (A B C: natset), A ⊆ B ∪ C → ∃ B' C', B' ⊆  B ∧ C' ⊆ C ∧ A ≡ B' ∪ C'.
@@ -131,8 +133,7 @@ Qed.
 
 Section compact_setoid.
   
-  From stdpp Require Import set.
-  From Coq Require Import Classical_Pred_Type.
+  Import stdpp.set Classical_Pred_Type.
 
   Definition set_finite_setoid `{Equiv A} {B} {H : ElemOf A B} (X : B) : Prop :=
     ∃ l : list A, ∀ x : A, x ∈ X → ∃ x' : A, x ≡ x' ∧ x' ∈ l.