fix for issue 731, needs optimization on existential queries
diff --git a/asterix-app/src/test/resources/optimizerts/queries/inverted-index-complex/ngram-edit-distance-check-substring.aql b/asterix-app/src/test/resources/optimizerts/queries/inverted-index-complex/ngram-edit-distance-check-substring.aql
new file mode 100644
index 0000000..a506053
--- /dev/null
+++ b/asterix-app/src/test/resources/optimizerts/queries/inverted-index-complex/ngram-edit-distance-check-substring.aql
@@ -0,0 +1,31 @@
+/*
+ * Description    : Tests whether an ngram_index index is applied to optimize a selection query using the similarity-edit-distance-check function on the substring of the field.
+ *                  Tests that the optimizer rule correctly drills through the substring function.
+ *                  The index should be applied.
+ * Success        : Yes
+ */
+
+drop dataverse test if exists;
+create dataverse test;
+use dataverse test;
+
+create type DBLPType as closed {
+  id: int32, 
+  dblpid: string,
+  title: string,
+  authors: string,
+  misc: string
+}
+
+create dataset DBLP(DBLPType) primary key id;
+
+create index ngram_index on DBLP(title) type ngram(3);
+
+write output to nc1:"rttest/inverted-index-complex_ngram-edit-distance-check-substring.adm";
+
+for $paper in dataset('DBLP')
+where edit-distance-check(substring($paper.title, 0, 8), "datbase", 1)[0]
+return {
+  "id" : $paper.id,
+  "title" : $paper.title
+}
\ No newline at end of file
diff --git a/asterix-app/src/test/resources/optimizerts/queries/inverted-index-complex/ngram-edit-distance-check-word-tokens.aql b/asterix-app/src/test/resources/optimizerts/queries/inverted-index-complex/ngram-edit-distance-check-word-tokens.aql
new file mode 100644
index 0000000..8f1c1fc
--- /dev/null
+++ b/asterix-app/src/test/resources/optimizerts/queries/inverted-index-complex/ngram-edit-distance-check-word-tokens.aql
@@ -0,0 +1,31 @@
+/*
+ * Description    : Tests whether an ngram_index index is applied to optimize a selection query using the similarity-edit-distance-check function on individual word tokens.
+ *                  Tests that the optimizer rule correctly drills through the word-tokens function and existential query.
+ *                  The index should be applied.
+ * Success        : Yes
+ */
+
+drop dataverse test if exists;
+create dataverse test;
+use dataverse test;
+
+create type DBLPType as closed {
+  id: int32, 
+  dblpid: string,
+  title: string,
+  authors: string,
+  misc: string
+}
+
+create dataset DBLP(DBLPType) primary key id;
+
+create index ngram_index on DBLP(title) type ngram(3);
+
+write output to nc1:"rttest/inverted-index-complex_ngram-edit-distance-check-word-tokens.adm";
+
+for $paper in dataset('DBLP')
+where (some $word in word-tokens($paper.title) satisfies edit-distance-check($word, "datbase", 1)[0] )
+return {
+  "id" : $paper.id,
+  "title" : $paper.title
+}
\ No newline at end of file
diff --git a/asterix-app/src/test/resources/optimizerts/results/inverted-index-complex/ngram-edit-distance-check-substring.plan b/asterix-app/src/test/resources/optimizerts/results/inverted-index-complex/ngram-edit-distance-check-substring.plan
new file mode 100644
index 0000000..259a003
--- /dev/null
+++ b/asterix-app/src/test/resources/optimizerts/results/inverted-index-complex/ngram-edit-distance-check-substring.plan
@@ -0,0 +1,19 @@
+-- DISTRIBUTE_RESULT  |PARTITIONED|
+  -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+    -- STREAM_PROJECT  |PARTITIONED|
+      -- ASSIGN  |PARTITIONED|
+        -- STREAM_SELECT  |PARTITIONED|
+          -- STREAM_PROJECT  |PARTITIONED|
+            -- ASSIGN  |PARTITIONED|
+              -- STREAM_PROJECT  |PARTITIONED|
+                -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                  -- BTREE_SEARCH  |PARTITIONED|
+                    -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                      -- STABLE_SORT [$$13(ASC)]  |PARTITIONED|
+                        -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                          -- STREAM_PROJECT  |PARTITIONED|
+                            -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                              -- LENGTH_PARTITIONED_INVERTED_INDEX_SEARCH  |PARTITIONED|
+                                -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                                  -- ASSIGN  |PARTITIONED|
+                                    -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
\ No newline at end of file
diff --git a/asterix-app/src/test/resources/optimizerts/results/inverted-index-complex/ngram-edit-distance-check-word-tokens.plan b/asterix-app/src/test/resources/optimizerts/results/inverted-index-complex/ngram-edit-distance-check-word-tokens.plan
new file mode 100644
index 0000000..e62a269
--- /dev/null
+++ b/asterix-app/src/test/resources/optimizerts/results/inverted-index-complex/ngram-edit-distance-check-word-tokens.plan
@@ -0,0 +1,24 @@
+-- DISTRIBUTE_RESULT  |PARTITIONED|
+  -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+    -- STREAM_PROJECT  |PARTITIONED|
+      -- ASSIGN  |PARTITIONED|
+        -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+          -- PRE_SORTED_DISTINCT_BY  |PARTITIONED|
+            -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+              -- STREAM_PROJECT  |PARTITIONED|
+                -- STREAM_SELECT  |PARTITIONED|
+                  -- UNNEST  |PARTITIONED|
+                    -- STREAM_PROJECT  |PARTITIONED|
+                      -- ASSIGN  |PARTITIONED|
+                        -- STREAM_PROJECT  |PARTITIONED|
+                          -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                            -- BTREE_SEARCH  |PARTITIONED|
+                              -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                                -- STABLE_SORT [$$16(ASC)]  |PARTITIONED|
+                                  -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                                    -- STREAM_PROJECT  |PARTITIONED|
+                                      -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                                        -- LENGTH_PARTITIONED_INVERTED_INDEX_SEARCH  |PARTITIONED|
+                                          -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                                            -- ASSIGN  |PARTITIONED|
+                                              -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
\ No newline at end of file
diff --git a/asterix-app/src/test/resources/optimizerts/results/q1.plan b/asterix-app/src/test/resources/optimizerts/results/q1.plan
index aa5daa2..3843154 100644
--- a/asterix-app/src/test/resources/optimizerts/results/q1.plan
+++ b/asterix-app/src/test/resources/optimizerts/results/q1.plan
@@ -2,19 +2,16 @@
   -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
     -- STREAM_PROJECT  |PARTITIONED|
       -- ASSIGN  |PARTITIONED|
-        -- STREAM_PROJECT  |PARTITIONED|
-          -- STREAM_SELECT  |PARTITIONED|
-            -- STREAM_PROJECT  |PARTITIONED|
-              -- SUBPLAN  |PARTITIONED|
-                      {
-                        -- AGGREGATE  |LOCAL|
-                          -- STREAM_SELECT  |LOCAL|
-                            -- UNNEST  |LOCAL|
-                              -- NESTED_TUPLE_SOURCE  |LOCAL|
-                      }
-                -- STREAM_PROJECT  |PARTITIONED|
-                  -- ASSIGN  |PARTITIONED|
-                    -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
-                      -- DATASOURCE_SCAN  |PARTITIONED|
-                        -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
-                          -- EMPTY_TUPLE_SOURCE  |PARTITIONED|
+        -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+          -- PRE_SORTED_DISTINCT_BY  |PARTITIONED|
+            -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+              -- STREAM_PROJECT  |PARTITIONED|
+                -- STREAM_SELECT  |PARTITIONED|
+                  -- STREAM_PROJECT  |PARTITIONED|
+                    -- UNNEST  |PARTITIONED|
+                      -- STREAM_PROJECT  |PARTITIONED|
+                        -- ASSIGN  |PARTITIONED|
+                          -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                            -- DATASOURCE_SCAN  |PARTITIONED|
+                              -- ONE_TO_ONE_EXCHANGE  |PARTITIONED|
+                                -- EMPTY_TUPLE_SOURCE  |PARTITIONED|