Get rid of annoying warning about 'Focus' in ErrorBounds.v

coq/ErrorBounds.v

@@ -88,12 +88,12 @@ Proof.
     apply Rabs_triang; apply Rplus_le_compat; try auto.
     rewrite Rplus_0_r.
     apply Rplus_le_compat; try auto. }
-  Focus 4.
-  eapply Rle_trans; [ apply Rabs_triang | rewrite (Rplus_assoc (Q2R err1)) ].
-  apply Rplus_le_compat; try auto.
-  eapply Rle_trans; [ apply Rabs_triang |].
-  apply Rplus_le_compat; try auto.
-  rewrite Rabs_Ropp; simpl. auto.
+  4: {
+    eapply Rle_trans; [ apply Rabs_triang | rewrite (Rplus_assoc (Q2R err1)) ].
+    apply Rplus_le_compat; try auto.
+    eapply Rle_trans; [ apply Rabs_triang |].
+    apply Rplus_le_compat; try auto.
+    rewrite Rabs_Ropp; simpl. auto. }
   all: eapply Rle_trans; try eapply H.
   all: setoid_rewrite Rplus_assoc at 2.
   all: eapply Rplus_le_compat; try auto.
@@ -164,7 +164,7 @@ Proof.
     apply Rplus_le_compat; try auto.
     rewrite Rplus_comm, <- Rsub_eq_Ropp_Rplus, Rabs_minus_sym.
     auto. }
-  Focus 4.
+  4: {
     eapply Rle_trans.
     apply Rabs_triang. setoid_rewrite Rplus_assoc at 2.
     apply Rplus_le_compat; try auto.
@@ -172,8 +172,7 @@ Proof.
     apply Rabs_triang.
     rewrite Rabs_Ropp. apply Rplus_le_compat; try auto.
     rewrite Rplus_comm, <- Rsub_eq_Ropp_Rplus, Rabs_minus_sym.
-    auto.
-
+    auto. }
   all: eapply Rle_trans; try eapply Rabs_triang.
   all: setoid_rewrite Rplus_assoc at 2.
   all: eapply Rplus_le_compat; try auto.
@@ -336,14 +335,13 @@ Proof.
   unfold computeErrorR.
   destruct m; rewrite Ropp_plus_distr.
   { rewrite Rplus_0_r; hnf; right; f_equal; lra. }
-  Focus 4.
-  rewrite <- Rplus_assoc.
-  eapply Rle_trans.
-  eapply Rabs_triang.
-  rewrite Rabs_Ropp.
-  eapply Rplus_le_compat; try auto.
-  hnf; right; f_equal; lra.
-
+  4: {
+    rewrite <- Rplus_assoc.
+    eapply Rle_trans.
+    eapply Rabs_triang.
+    rewrite Rabs_Ropp.
+    eapply Rplus_le_compat; try auto.
+    hnf; right; f_equal; lra. }
   all: repeat rewrite <- Rplus_assoc.
   all: setoid_rewrite <- Rsub_eq_Ropp_Rplus at 2.
   all: repeat rewrite Rsub_eq_Ropp_Rplus.