diff --git a/dist b/dist
index 5e295b80..8ba1e4ce 160000
--- a/dist
+++ b/dist
@@ -1 +1 @@
-Subproject commit 5e295b80d793748515957c5d309d2f8e8e83af29
+Subproject commit 8ba1e4ce27a75bb025a5478723ea57f7f437ccf0
diff --git a/src/Database.js b/src/Database.js
index 438be1a9..5ad9f4a8 100644
--- a/src/Database.js
+++ b/src/Database.js
@@ -365,7 +365,7 @@ module.exports = function (Y /* :any */) {
           yield* Y.Struct['Delete'].execute.call(transaction, delop)
         }
 
-        // notify parent, if it has been initialized as a custom type
+        // notify parent, if it was instanciated as a custom type
         if (t != null) {
           yield* t._changed(transaction, Y.utils.copyObject(op))
         }
diff --git a/src/Database.spec.js b/src/Database.spec.js
index 0a91044d..4aa3a825 100644
--- a/src/Database.spec.js
+++ b/src/Database.spec.js
@@ -23,7 +23,7 @@ for (let database of databases) {
         })
         it('Deleted operation is deleted', async(function * (done) {
           store.requestTransaction(function * () {
-            yield* this.markDeleted(['u1', 10])
+            yield* this.markDeleted(['u1', 10], 1)
             expect(yield* this.isDeleted(['u1', 10])).toBeTruthy()
             expect(yield* this.getDeleteSet()).toEqual({'u1': [[10, 1, false]]})
             done()
@@ -31,8 +31,8 @@ for (let database of databases) {
         }))
         it('Deleted operation extends other deleted operation', async(function * (done) {
           store.requestTransaction(function * () {
-            yield* this.markDeleted(['u1', 10])
-            yield* this.markDeleted(['u1', 11])
+            yield* this.markDeleted(['u1', 10], 1)
+            yield* this.markDeleted(['u1', 11], 1)
             expect(yield* this.isDeleted(['u1', 10])).toBeTruthy()
             expect(yield* this.isDeleted(['u1', 11])).toBeTruthy()
             expect(yield* this.getDeleteSet()).toEqual({'u1': [[10, 2, false]]})
@@ -41,35 +41,35 @@ for (let database of databases) {
         }))
         it('Deleted operation extends other deleted operation', async(function * (done) {
           store.requestTransaction(function * () {
-            yield* this.markDeleted(['0', 3])
-            yield* this.markDeleted(['0', 4])
-            yield* this.markDeleted(['0', 2])
+            yield* this.markDeleted(['0', 3], 1)
+            yield* this.markDeleted(['0', 4], 1)
+            yield* this.markDeleted(['0', 2], 1)
             expect(yield* this.getDeleteSet()).toEqual({'0': [[2, 3, false]]})
             done()
           })
         }))
         it('Debug #1', async(function * (done) {
           store.requestTransaction(function * () {
-            yield* this.markDeleted(['166', 0])
-            yield* this.markDeleted(['166', 2])
-            yield* this.markDeleted(['166', 0])
-            yield* this.markDeleted(['166', 2])
+            yield* this.markDeleted(['166', 0], 1)
+            yield* this.markDeleted(['166', 2], 1)
+            yield* this.markDeleted(['166', 0], 1)
+            yield* this.markDeleted(['166', 2], 1)
             yield* this.markGarbageCollected(['166', 2], 1)
-            yield* this.markDeleted(['166', 1])
-            yield* this.markDeleted(['166', 3])
+            yield* this.markDeleted(['166', 1], 1)
+            yield* this.markDeleted(['166', 3], 1)
             yield* this.markGarbageCollected(['166', 3], 1)
-            yield* this.markDeleted(['166', 0])
+            yield* this.markDeleted(['166', 0], 1)
             expect(yield* this.getDeleteSet()).toEqual({'166': [[0, 2, false], [2, 2, true]]})
             done()
           })
         }))
         it('Debug #2', async(function * (done) {
           store.requestTransaction(function * () {
-            yield* this.markDeleted(['293', 0])
-            yield* this.markDeleted(['291', 2])
-            yield* this.markDeleted(['291', 2])
+            yield* this.markDeleted(['293', 0], 1)
+            yield* this.markDeleted(['291', 2], 1)
+            yield* this.markDeleted(['291', 2], 1)
             yield* this.markGarbageCollected(['293', 0], 1)
-            yield* this.markDeleted(['293', 1])
+            yield* this.markDeleted(['293', 1], 1)
             yield* this.markGarbageCollected(['291', 2], 1)
             expect(yield* this.getDeleteSet()).toEqual({'291': [[2, 1, true]], '293': [[0, 1, true], [1, 1, false]]})
             done()
@@ -77,16 +77,16 @@ for (let database of databases) {
         }))
         it('Debug #3', async(function * (done) {
           store.requestTransaction(function * () {
-            yield* this.markDeleted(['581', 0])
-            yield* this.markDeleted(['581', 1])
-            yield* this.markDeleted(['580', 0])
-            yield* this.markDeleted(['580', 0])
+            yield* this.markDeleted(['581', 0], 1)
+            yield* this.markDeleted(['581', 1], 1)
+            yield* this.markDeleted(['580', 0], 1)
+            yield* this.markDeleted(['580', 0], 1)
             yield* this.markGarbageCollected(['581', 0], 1)
-            yield* this.markDeleted(['581', 2])
-            yield* this.markDeleted(['580', 1])
-            yield* this.markDeleted(['580', 2])
-            yield* this.markDeleted(['580', 1])
-            yield* this.markDeleted(['580', 2])
+            yield* this.markDeleted(['581', 2], 1)
+            yield* this.markDeleted(['580', 1], 1)
+            yield* this.markDeleted(['580', 2], 1)
+            yield* this.markDeleted(['580', 1], 1)
+            yield* this.markDeleted(['580', 2], 1)
             yield* this.markGarbageCollected(['581', 2], 1)
             yield* this.markGarbageCollected(['581', 1], 1)
             yield* this.markGarbageCollected(['580', 1], 1)
@@ -96,18 +96,18 @@ for (let database of databases) {
         }))
         it('Debug #4', async(function * (done) {
           store.requestTransaction(function * () {
-            yield* this.markDeleted(['544', 0])
-            yield* this.markDeleted(['543', 2])
-            yield* this.markDeleted(['544', 0])
-            yield* this.markDeleted(['543', 2])
+            yield* this.markDeleted(['544', 0], 1)
+            yield* this.markDeleted(['543', 2], 1)
+            yield* this.markDeleted(['544', 0], 1)
+            yield* this.markDeleted(['543', 2], 1)
             yield* this.markGarbageCollected(['544', 0], 1)
-            yield* this.markDeleted(['545', 1])
-            yield* this.markDeleted(['543', 4])
-            yield* this.markDeleted(['543', 3])
-            yield* this.markDeleted(['544', 1])
-            yield* this.markDeleted(['544', 2])
-            yield* this.markDeleted(['544', 1])
-            yield* this.markDeleted(['544', 2])
+            yield* this.markDeleted(['545', 1], 1)
+            yield* this.markDeleted(['543', 4], 1)
+            yield* this.markDeleted(['543', 3], 1)
+            yield* this.markDeleted(['544', 1], 1)
+            yield* this.markDeleted(['544', 2], 1)
+            yield* this.markDeleted(['544', 1], 1)
+            yield* this.markDeleted(['544', 2], 1)
             yield* this.markGarbageCollected(['543', 2], 1)
             yield* this.markGarbageCollected(['543', 4], 1)
             yield* this.markGarbageCollected(['544', 2], 1)
@@ -136,21 +136,21 @@ for (let database of databases) {
         }))
         it('Debug #7', async(function * (done) {
           store.requestTransaction(function * () {
-            yield* this.markDeleted(['9', 2])
-            yield* this.markDeleted(['11', 2])
-            yield* this.markDeleted(['11', 4])
-            yield* this.markDeleted(['11', 1])
-            yield* this.markDeleted(['9', 4])
-            yield* this.markDeleted(['10', 0])
+            yield* this.markDeleted(['9', 2], 1)
+            yield* this.markDeleted(['11', 2], 1)
+            yield* this.markDeleted(['11', 4], 1)
+            yield* this.markDeleted(['11', 1], 1)
+            yield* this.markDeleted(['9', 4], 1)
+            yield* this.markDeleted(['10', 0], 1)
             yield* this.markGarbageCollected(['11', 2], 1)
-            yield* this.markDeleted(['11', 2])
+            yield* this.markDeleted(['11', 2], 1)
             yield* this.markGarbageCollected(['11', 3], 1)
-            yield* this.markDeleted(['11', 3])
-            yield* this.markDeleted(['11', 3])
-            yield* this.markDeleted(['9', 4])
-            yield* this.markDeleted(['10', 0])
+            yield* this.markDeleted(['11', 3], 1)
+            yield* this.markDeleted(['11', 3], 1)
+            yield* this.markDeleted(['9', 4], 1)
+            yield* this.markDeleted(['10', 0], 1)
             yield* this.markGarbageCollected(['11', 1], 1)
-            yield* this.markDeleted(['11', 1])
+            yield* this.markDeleted(['11', 1], 1)
             expect(yield* this.getDeleteSet()).toEqual({'9': [[2, 1, false], [4, 1, false]], '10': [[0, 1, false]], '11': [[1, 3, true], [4, 1, false]]})
             done()
           })
diff --git a/src/Struct.js b/src/Struct.js
index 66381278..de0c5f54 100644
--- a/src/Struct.js
+++ b/src/Struct.js
@@ -127,7 +127,7 @@ module.exports = function (Y/* :any */) {
         var i // loop counter
         var distanceToOrigin = i = yield* Struct.Insert.getDistanceToOrigin.call(this, op) // most cases: 0 (starts from 0)
 
-        if (op.origin != null) {
+        if (op.origin != null) { // TODO: !== instead of !=
           // we save in origin that op originates in it
           // we need that later when we eventually garbage collect origin (see transaction)
           var origin = yield* this.getOperation(op.origin)
diff --git a/src/Transaction.js b/src/Transaction.js
index 46ba388a..691afb1d 100644
--- a/src/Transaction.js
+++ b/src/Transaction.js
@@ -150,7 +150,7 @@ module.exports = function (Y/* :any */) {
       var callType = false
 
       if (target == null || !target.deleted) {
-        yield* this.markDeleted(targetId)
+        yield* this.markDeleted(targetId, 1)
       }
 
       if (target != null && target.gc == null) {
@@ -274,7 +274,8 @@ module.exports = function (Y/* :any */) {
     * markDeleted (id, length) {
       if (length == null) {
         length = 1
-        // debugger // TODO!!
+        debugger // TODO!!
+        throw new Error("dtrnd")
       }
       // this.mem.push(["del", id]);
       var n = yield* this.ds.findWithUpperBound(id)