diff --git a/test/intersection1.query b/test/intersection1.query
new file mode 100644
index 0000000..aa82516
--- /dev/null
+++ b/test/intersection1.query
@@ -0,0 +1 @@
+σ name=='eve' (people) ᑎ people
diff --git a/test/intersection1.result b/test/intersection1.result
new file mode 100644
index 0000000..09dd8f0
--- /dev/null
+++ b/test/intersection1.result
@@ -0,0 +1,2 @@
+id,name,chief,age
+4,eve,0,25
diff --git a/test/intersection2.query b/test/intersection2.query
new file mode 100644
index 0000000..216f4e4
--- /dev/null
+++ b/test/intersection2.query
@@ -0,0 +1 @@
+people ᑎ σ name=='eve' (people)
diff --git a/test/intersection2.result b/test/intersection2.result
new file mode 100644
index 0000000..09dd8f0
--- /dev/null
+++ b/test/intersection2.result
@@ -0,0 +1,2 @@
+id,name,chief,age
+4,eve,0,25
diff --git a/test/subtraction1.query b/test/subtraction1.query
new file mode 100644
index 0000000..77dad2d
--- /dev/null
+++ b/test/subtraction1.query
@@ -0,0 +1 @@
+people - σ name=='eve'(people)
diff --git a/test/subtraction1.result b/test/subtraction1.result
new file mode 100644
index 0000000..6dc5c97
--- /dev/null
+++ b/test/subtraction1.result
@@ -0,0 +1,8 @@
+id,name,chief,age
+3,dean,1,33
+6,paul,4,30
+2,john,1,30
+0,jack,0,22
+7,alia,1,28
+1,carl,0,20
+5,duncan,4,30
diff --git a/test/union1.query b/test/union1.query
new file mode 100644
index 0000000..200d663
--- /dev/null
+++ b/test/union1.query
@@ -0,0 +1 @@
+σ age<30 (σ (id%2==0) (people) ᑌ σ age>22(people))
diff --git a/test/union1.result b/test/union1.result
new file mode 100644
index 0000000..dea402b
--- /dev/null
+++ b/test/union1.result
@@ -0,0 +1,4 @@
+id,name,chief,age
+7,alia,1,28
+4,eve,0,25
+0,jack,0,22
diff --git a/test/union2.query b/test/union2.query
new file mode 100644
index 0000000..61a3569
--- /dev/null
+++ b/test/union2.query
@@ -0,0 +1 @@
+people ᑌ σ name=='eve' (people)
diff --git a/test/union2.result b/test/union2.result
new file mode 100644
index 0000000..0c5da4e
--- /dev/null
+++ b/test/union2.result
@@ -0,0 +1,9 @@
+id,name,chief,age
+3,dean,1,33
+6,paul,4,30
+2,john,1,30
+0,jack,0,22
+7,alia,1,28
+1,carl,0,20
+4,eve,0,25
+5,duncan,4,30
diff --git a/test/union3.query b/test/union3.query
new file mode 100644
index 0000000..1643a1d
--- /dev/null
+++ b/test/union3.query
@@ -0,0 +1 @@
+σ name=='eve' (people) ᑌ people
diff --git a/test/union3.result b/test/union3.result
new file mode 100644
index 0000000..0c5da4e
--- /dev/null
+++ b/test/union3.result
@@ -0,0 +1,9 @@
+id,name,chief,age
+3,dean,1,33
+6,paul,4,30
+2,john,1,30
+0,jack,0,22
+7,alia,1,28
+1,carl,0,20
+4,eve,0,25
+5,duncan,4,30