diff --git a/SQL Hell pt3.txt b/Semester 2/SQL Hell pt3.txt
similarity index 100%
rename from SQL Hell pt3.txt
rename to Semester 2/SQL Hell pt3.txt
diff --git a/Semester 2/SQL Hell pt4.txt b/Semester 2/SQL Hell pt4.txt
new file mode 100644
index 0000000..69339ca
--- /dev/null
+++ b/Semester 2/SQL Hell pt4.txt	
@@ -0,0 +1,45 @@
+/* What are the suppliers that supply all parts using NOT EXISTS */
+/* sp difference A */
+select DISTINCT snumber
+from spj as c
+where not EXISTS 
+/* A */
+/* Cross Product */
+(select DISTINCT b.snumber
+ from part as a cross join spj as b 
+ where c.snumber = b.snumber and not EXISTS
+ /* difference cross product sp */
+ (select snumber, pnumber from spj
+  where b.snumber = spj.snumber and a.pnumber = spj.pnumber));
+
+  
+  /* What are the suppliers that supply all parts using NOT EXISTS * */
+/* sp difference A */
+select DISTINCT snumber
+from spj as c
+where not EXISTS 
+/* A */
+/* Cross Product */
+(select *
+ from part as a cross join spj as b 
+ where c.snumber = b.snumber and not EXISTS
+ /* difference cross product sp */
+ (select * from spj
+  where b.snumber = spj.snumber and a.pnumber = spj.pnumber));
+  
+  
+/* What are the suppliers that supply all parts using NOT EXISTS *, list their names and their cities */
+select snumber, sname, city from supplier
+WHERE snumber in
+(/* sp difference A */
+select DISTINCT snumber
+from spj as c
+where not EXISTS 
+/* A */
+/* Cross Product */
+(select *
+ from part as a cross join spj as b 
+ where c.snumber = b.snumber and not EXISTS
+ /* difference cross product sp */
+ (select * from spj
+  where b.snumber = spj.snumber and a.pnumber = spj.pnumber)));
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diff --git a/lamp/mysql/#innodb_temp/temp_8.ibt b/lamp/mysql/#innodb_temp/temp_8.ibt
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diff --git a/lamp/mysql/#innodb_temp/temp_9.ibt b/lamp/mysql/#innodb_temp/temp_9.ibt
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diff --git a/lamp/mysql/binlog.000019 b/lamp/mysql/binlog.000019
deleted file mode 100755
index fb6d860..0000000
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diff --git a/lamp/mysql/binlog.000035 b/lamp/mysql/binlog.000035
old mode 100644
new mode 100755
index 977c7e7..9c1f72d
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diff --git a/lamp/mysql/binlog.000036 b/lamp/mysql/binlog.000036
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index 0000000..2ed1acd
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diff --git a/lamp/mysql/binlog.index b/lamp/mysql/binlog.index
index 11aab58..60a329c 100644
--- a/lamp/mysql/binlog.index
+++ b/lamp/mysql/binlog.index
@@ -1,4 +1,3 @@
-./binlog.000019
 ./binlog.000020
 ./binlog.000021
 ./binlog.000022
@@ -14,3 +13,4 @@
 ./binlog.000033
 ./binlog.000034
 ./binlog.000035
+./binlog.000036
diff --git a/lamp/mysql/d6a8f2b56d7f.pid b/lamp/mysql/d6a8f2b56d7f.pid
new file mode 100644
index 0000000..730a054
--- /dev/null
+++ b/lamp/mysql/d6a8f2b56d7f.pid
@@ -0,0 +1 @@
+172
diff --git a/lamp/mysql/e986610d0834.pid b/lamp/mysql/e986610d0834.pid
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