From 7f4876445ce759edb5804ddc00897e30899c029c Mon Sep 17 00:00:00 2001
From: Scott J Miles <sjmiles@google.com>
Date: Wed, 13 May 2015 11:21:04 -0700
Subject: [PATCH 1/3] propagate `negate` flag from `note` to `effect`

---
 src/standard/effects.html | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/standard/effects.html b/src/standard/effects.html
index f16cc212a7..639f9f7fc2 100644
--- a/src/standard/effects.html
+++ b/src/standard/effects.html
@@ -173,7 +173,8 @@
           args: sig.args,
           arg: arg,
           property: note.name,
-          index: index
+          index: index,
+          negate: note.negate
         });
       }, this);
     },

From 36a3251117f05a2b9c2a69b9a5db9141bc885215 Mon Sep 17 00:00:00 2001
From: Scott J Miles <sjmiles@google.com>
Date: Wed, 13 May 2015 11:22:11 -0700
Subject: [PATCH 2/3] negate value in annotated computation if `effect.negate`
 is true (ultimately all effect-flag value mutations should be in one place,
 aka expressions)

---
 src/lib/bind/effects.html | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/lib/bind/effects.html b/src/lib/bind/effects.html
index 765928bfaf..4b2a494dcf 100644
--- a/src/lib/bind/effects.html
+++ b/src/lib/bind/effects.html
@@ -71,6 +71,9 @@
         var computedHost = this._rootDataHost || this;
         var computedvalue =
           computedHost[effect.method].apply(computedHost, args);
+        if (effect.negate) {
+          computedvalue = !computedvalue;
+        }
         this._applyEffectValue(computedvalue, effect);
       }
     },

From 2efcb601a922aa3c5a6662aeed775f7f12b9f8db Mon Sep 17 00:00:00 2001
From: Scott J Miles <sjmiles@google.com>
Date: Wed, 13 May 2015 11:22:31 -0700
Subject: [PATCH 3/3] test for `{{!computed(prop)}}`

---
 test/unit/bind-elements.html | 1 +
 test/unit/bind.html          | 1 +
 2 files changed, 2 insertions(+)

diff --git a/test/unit/bind-elements.html b/test/unit/bind-elements.html
index b481671dbe..56ba8a61bf 100644
--- a/test/unit/bind-elements.html
+++ b/test/unit/bind-elements.html
@@ -9,6 +9,7 @@
     computed-inline="{{computeInline(value,add, divide)}}"
     computed-inline2="{{computeInline(value, add,divide)}}"
     computedattribute$="{{computeInline(value, add,divide)}}"
+    neg-computed-inline="{{!computeInline(value,add,divide)}}"
     style$="{{boundStyle}}"
     data-id$="{{dataSetId}}"
     custom-event-value="{{customEventValue::custom}}"
diff --git a/test/unit/bind.html b/test/unit/bind.html
index 1b18c81bd3..6963bec6ff 100644
--- a/test/unit/bind.html
+++ b/test/unit/bind.html
@@ -160,6 +160,7 @@
     el.divide = 3;
     assert.equal(el.$.boundChild.computedInline, 20, 'computedInline not correct');
     assert.equal(el.$.boundChild.computedInline2, 20, 'computedInline2 not correct');
+    assert.equal(el.$.boundChild.negComputedInline, false, 'negComputedInline not correct');
   });
 
   test('annotated computed attribute', function() {