diff --git a/collects/tests/datalog/ast.rkt b/collects/tests/datalog/ast.rkt
new file mode 100644
index 0000000000..ec6e6eeff0
--- /dev/null
+++ b/collects/tests/datalog/ast.rkt
@@ -0,0 +1,80 @@
+#lang racket
+(require rackunit
+         datalog/ast)
+
+(provide ast-tests)
+
+(define ast-tests
+  (test-suite
+   "ast"
+   
+   (test-suite
+    "datum-equal?"
+    (test-not-false "str/str" (datum-equal? "str" "str"))
+    (test-false "str/str" (datum-equal? "str1" "str2"))
+    (test-not-false "sym/sym" (datum-equal? 'sym1 'sym1))
+    (test-false "sym/sym" (datum-equal? 'sym1 'sym2))
+    (test-false "str/sym" (datum-equal? "str" 'sym))
+    (test-false "sym/str" (datum-equal? 'sym "str")))
+   
+   (test-suite
+    "variable-equal?"
+    (test-not-false "var/var" (variable-equal? (make-variable #f 'sym1) (make-variable #f 'sym1)))
+    (test-not-false "var/var" (variable-equal? (make-variable #f 'sym1) (make-variable #'sym1 'sym1)))
+    (test-false "var/var" (variable-equal? (make-variable #f 'sym1) (make-variable #f 'sym2)))
+    (test-false "var/var" (variable-equal? (make-variable #f 'sym1) (make-variable #'sym2 'sym2))))
+   
+   (test-suite
+    "constant-equal?"
+    (test-not-false "sym/sym" (constant-equal? (make-constant #f 'sym1) (make-constant #f 'sym1)))
+    (test-not-false "sym/sym" (constant-equal? (make-constant #f 'sym1) (make-constant #'sym1 'sym1)))
+    (test-false "sym/sym" (constant-equal? (make-constant #f 'sym1) (make-constant #'sym1 'sym2)))
+    (test-not-false "str/str" (constant-equal? (make-constant #f "sym1") (make-constant #f "sym1")))
+    (test-not-false "str/str" (constant-equal? (make-constant #f "sym1") (make-constant #'sym1 "sym1")))
+    (test-false "str/str" (constant-equal? (make-constant #f "sym1") (make-constant #'sym1 "sym2")))
+    (test-false "sym/str" (constant-equal? (make-constant #f 'sym1) (make-constant #'sym1 "sym2")))
+    (test-false "str/sym" (constant-equal? (make-constant #'sym1 "sym2") (make-constant #f 'sym1))))
+   
+   (test-suite
+    "term-equal?"
+    (test-not-false "var/var" (term-equal? (make-variable #f 'sym1) (make-variable #f 'sym1)))
+    (test-not-false "var/var" (term-equal? (make-variable #f 'sym1) (make-variable #'sym1 'sym1)))
+    (test-false "var/var" (term-equal? (make-variable #f 'sym1) (make-variable #f 'sym2)))
+    (test-false "var/var" (term-equal? (make-variable #f 'sym1) (make-variable #'sym2 'sym2)))
+    (test-not-false "sym/sym" (term-equal? (make-constant #f 'sym1) (make-constant #f 'sym1)))
+    (test-not-false "sym/sym" (term-equal? (make-constant #f 'sym1) (make-constant #'sym1 'sym1)))
+    (test-false "sym/sym" (term-equal? (make-constant #f 'sym1) (make-constant #'sym1 'sym2)))
+    (test-not-false "str/str" (term-equal? (make-constant #f "sym1") (make-constant #f "sym1")))
+    (test-not-false "str/str" (term-equal? (make-constant #f "sym1") (make-constant #'sym1 "sym1")))
+    (test-false "str/str" (term-equal? (make-constant #f "sym1") (make-constant #'sym1 "sym2")))
+    (test-false "sym/str" (term-equal? (make-constant #f 'sym1) (make-constant #'sym1 "sym2")))
+    (test-false "str/sym" (term-equal? (make-constant #'sym1 "sym2") (make-constant #f 'sym1)))    
+    (test-false "con/var" (term-equal? (make-constant #'sym1 "sym2") (make-variable #f 'sym1)))
+    (test-false "var/con" (term-equal? (make-variable #f 'sym1) (make-constant #'sym1 "sym2"))))
+   
+   (test-suite
+    "literal-equal?"
+    (test-not-false "lit" (literal-equal? (make-literal #f 'lit1 empty) (make-literal #'lit1 'lit1 empty)))
+    (test-not-false "lit" (literal-equal? (make-literal #f 'lit1 (list (make-variable #f 'sym1)))
+                                          (make-literal #'lit1 'lit1 (list (make-variable #f 'sym1)))))
+    (test-not-false "lit" (literal-equal? (make-literal #f 'lit1 (list (make-variable #f 'sym1)))
+                                          (make-literal #'lit1 'lit1 (list (make-variable #'sym1 'sym1)))))
+    (test-false "lit" (literal-equal? (make-literal #f 'lit1 empty) (make-literal #'lit1 'lit2 empty)))
+    (test-false "lit" (literal-equal? (make-literal #f 'lit1 (list (make-variable #f 'sym1))) (make-literal #'lit1 'lit2 empty)))
+    (test-false "lit" (literal-equal? (make-literal #f 'lit1 (list (make-variable #f 'sym1)))
+                                      (make-literal #'lit1 'lit2 (list (make-variable #'sym1 'sym2))))))
+   
+   (test-suite
+    "clause-equal?"
+    (test-not-false "lit" (clause-equal? (make-clause #f (make-literal #f 'lit1 empty) empty)
+                                         (make-clause #f (make-literal #f 'lit1 empty) empty)))
+    (test-not-false "lit" (clause-equal? (make-clause #f (make-literal #f 'lit1 empty) (list (make-literal #f 'lit1 empty)))
+                                         (make-clause #f (make-literal #f 'lit1 empty) (list (make-literal #f 'lit1 empty)))))
+    (test-not-false "lit" (clause-equal? (make-clause #f (make-literal #f 'lit1 empty) empty)
+                                         (make-clause #'cl1 (make-literal #f 'lit1 empty) empty)))
+    (test-false "lit" (clause-equal? (make-clause #f (make-literal #f 'lit1 empty) empty)
+                                     (make-clause #f (make-literal #f 'lit2 empty) empty)))
+    (test-false "lit" (clause-equal? (make-clause #f (make-literal #f 'lit1 empty) (list (make-literal #f 'lit1 empty)))
+                                     (make-clause #f (make-literal #f 'lit1 empty) empty)))
+    (test-false "lit" (clause-equal? (make-clause #f (make-literal #f 'lit1 empty) (list (make-literal #f 'lit1 empty)))
+                                     (make-clause #f (make-literal #f 'lit1 empty) (list (make-literal #f 'lit2 empty))))))))
\ No newline at end of file
diff --git a/collects/tests/datalog/eval.rkt b/collects/tests/datalog/eval.rkt
new file mode 100644
index 0000000000..8864bd6639
--- /dev/null
+++ b/collects/tests/datalog/eval.rkt
@@ -0,0 +1,47 @@
+#lang racket
+(require rackunit
+         racket/runtime-path
+         datalog/parse
+         datalog/eval)
+
+(provide eval-tests)
+
+(define-runtime-path here ".")
+
+(define (test-examples examples-dir)
+  
+  (define (test-example t)
+    (define test-rkt (build-path examples-dir (format "~a.rkt" t)))
+    (define test-txt (build-path examples-dir (format "~a.txt" t)))
+    (test-equal? t
+                 (filter (lambda (l)
+                           (not (string=? l "")))
+                         (with-input-from-string
+                             (with-output-to-string
+                                 (lambda () (dynamic-require test-rkt #f)))
+                           port->lines))
+                 (filter (lambda (l)
+                           (not (string=? l "")))
+                         (file->lines test-txt))
+                 ))
+  
+  (test-suite
+   (path->string examples-dir)
+   
+   (test-example "ancestor")
+   (test-example "bidipath")
+   (test-example "laps")
+   (test-example "long")
+   (test-example "path")
+   (test-example "pq")
+   (test-example "revpath")
+   (test-example "says")
+   (test-example "true")
+   (test-example "tutorial")))
+
+(define eval-tests
+  (test-suite
+   "eval"
+   
+   (test-examples (build-path here "examples"))
+   (test-examples (build-path here "paren-examples"))))
\ No newline at end of file
diff --git a/collects/tests/datalog/examples/ancestor.rkt b/collects/tests/datalog/examples/ancestor.rkt
new file mode 100644
index 0000000000..f448960203
--- /dev/null
+++ b/collects/tests/datalog/examples/ancestor.rkt
@@ -0,0 +1,12 @@
+#lang datalog
+% Equality test
+ancestor(A, B) :-
+    parent(A, B).
+ancestor(A, B) :-
+    parent(A, C),
+    D = C,      % Unification required
+    ancestor(D, B).
+parent(john, douglas).
+parent(bob, john).
+parent(ebbon, bob).
+ancestor(A, B)?
\ No newline at end of file
diff --git a/collects/tests/datalog/examples/ancestor.txt b/collects/tests/datalog/examples/ancestor.txt
new file mode 100644
index 0000000000..bed107f84b
--- /dev/null
+++ b/collects/tests/datalog/examples/ancestor.txt
@@ -0,0 +1,6 @@
+ancestor(ebbon, bob).
+ancestor(bob, john).
+ancestor(john, douglas).
+ancestor(bob, douglas).
+ancestor(ebbon, john).
+ancestor(ebbon, douglas).
diff --git a/collects/tests/datalog/examples/bidipath.rkt b/collects/tests/datalog/examples/bidipath.rkt
new file mode 100644
index 0000000000..cb1393bdc2
--- /dev/null
+++ b/collects/tests/datalog/examples/bidipath.rkt
@@ -0,0 +1,7 @@
+#lang datalog
+% path test from Chen & Warren
+edge(a, b). edge(b, c). edge(c, d). edge(d, a).
+path(X, Y) :- edge(X, Y).
+path(X, Y) :- edge(X, Z), path(Z, Y).
+path(X, Y) :- path(X, Z), edge(Z, Y).
+path(X, Y)?
diff --git a/collects/tests/datalog/examples/bidipath.txt b/collects/tests/datalog/examples/bidipath.txt
new file mode 100644
index 0000000000..6c197dd6eb
--- /dev/null
+++ b/collects/tests/datalog/examples/bidipath.txt
@@ -0,0 +1,17 @@
+path(a, a).
+path(a, d).
+path(a, c).
+path(a, b).
+path(b, b).
+path(b, a).
+path(b, d).
+path(b, c).
+path(c, c).
+path(c, b).
+path(c, a).
+path(c, d).
+path(d, d).
+path(d, c).
+path(d, b).
+path(d, a).
+
diff --git a/collects/tests/datalog/examples/laps.rkt b/collects/tests/datalog/examples/laps.rkt
new file mode 100644
index 0000000000..56bac6624a
--- /dev/null
+++ b/collects/tests/datalog/examples/laps.rkt
@@ -0,0 +1,12 @@
+#lang datalog
+% Laps Test
+contains(ca, store, rams_couch, rams).
+contains(rams, fetch, rams_couch, will).
+contains(ca, fetch, Name, Watcher) :-
+    contains(ca, store, Name, Owner),
+    contains(Owner, fetch, Name, Watcher).
+trusted(ca).
+permit(User, Priv, Name) :-
+    contains(Auth, Priv, Name, User),
+    trusted(Auth).
+permit(User, Priv, Name)?
diff --git a/collects/tests/datalog/examples/laps.txt b/collects/tests/datalog/examples/laps.txt
new file mode 100644
index 0000000000..d87ea5fb54
--- /dev/null
+++ b/collects/tests/datalog/examples/laps.txt
@@ -0,0 +1,2 @@
+permit(rams, store, rams_couch).
+permit(will, fetch, rams_couch).
diff --git a/collects/tests/datalog/examples/long.rkt b/collects/tests/datalog/examples/long.rkt
new file mode 100644
index 0000000000..a8b9912662
--- /dev/null
+++ b/collects/tests/datalog/examples/long.rkt
@@ -0,0 +1,8 @@
+#lang datalog
+abcdefghi(z123456789,
+z1234567890123456789,
+z123456789012345678901234567890123456789,
+z1234567890123456789012345678901234567890123456789012345678901234567890123456789).
+
+this_is_a_long_identifier_and_tests_the_scanners_concat_when_read_with_a_small_buffer.
+this_is_a_long_identifier_and_tests_the_scanners_concat_when_read_with_a_small_buffer?
diff --git a/collects/tests/datalog/examples/long.txt b/collects/tests/datalog/examples/long.txt
new file mode 100644
index 0000000000..ebf5669da9
--- /dev/null
+++ b/collects/tests/datalog/examples/long.txt
@@ -0,0 +1 @@
+this_is_a_long_identifier_and_tests_the_scanners_concat_when_read_with_a_small_buffer.
diff --git a/collects/tests/datalog/examples/path.rkt b/collects/tests/datalog/examples/path.rkt
new file mode 100644
index 0000000000..694aaab53f
--- /dev/null
+++ b/collects/tests/datalog/examples/path.rkt
@@ -0,0 +1,6 @@
+#lang datalog
+% path test from Chen & Warren
+edge(a, b). edge(b, c). edge(c, d). edge(d, a).
+path(X, Y) :- edge(X, Y).
+path(X, Y) :- edge(X, Z), path(Z, Y).
+path(X, Y)?
diff --git a/collects/tests/datalog/examples/path.txt b/collects/tests/datalog/examples/path.txt
new file mode 100644
index 0000000000..cfe9daed0a
--- /dev/null
+++ b/collects/tests/datalog/examples/path.txt
@@ -0,0 +1,17 @@
+path(a, a).
+path(a, d).
+path(a, c).
+path(a, b).
+path(b, a).
+path(b, d).
+path(b, c).
+path(b, b).
+path(c, a).
+path(c, b).
+path(c, c).
+path(c, d).
+path(d, b).
+path(d, c).
+path(d, d).
+path(d, a).
+
diff --git a/collects/tests/datalog/examples/pq.rkt b/collects/tests/datalog/examples/pq.rkt
new file mode 100644
index 0000000000..c5efcec2a0
--- /dev/null
+++ b/collects/tests/datalog/examples/pq.rkt
@@ -0,0 +1,6 @@
+#lang datalog
+% p q test from Chen & Warren
+q(X) :- p(X).
+q(a).
+p(X) :- q(X).
+q(X)?
diff --git a/collects/tests/datalog/examples/pq.txt b/collects/tests/datalog/examples/pq.txt
new file mode 100644
index 0000000000..7526e512b1
--- /dev/null
+++ b/collects/tests/datalog/examples/pq.txt
@@ -0,0 +1 @@
+q(a).
diff --git a/collects/tests/datalog/examples/revpath.rkt b/collects/tests/datalog/examples/revpath.rkt
new file mode 100644
index 0000000000..15d8fe959a
--- /dev/null
+++ b/collects/tests/datalog/examples/revpath.rkt
@@ -0,0 +1,6 @@
+#lang datalog
+% path test from Chen & Warren
+edge(a, b). edge(b, c). edge(c, d). edge(d, a).
+path(X, Y) :- edge(X, Y).
+path(X, Y) :- path(X, Z), edge(Z, Y).
+path(X, Y)?
diff --git a/collects/tests/datalog/examples/revpath.txt b/collects/tests/datalog/examples/revpath.txt
new file mode 100644
index 0000000000..6c197dd6eb
--- /dev/null
+++ b/collects/tests/datalog/examples/revpath.txt
@@ -0,0 +1,17 @@
+path(a, a).
+path(a, d).
+path(a, c).
+path(a, b).
+path(b, b).
+path(b, a).
+path(b, d).
+path(b, c).
+path(c, c).
+path(c, b).
+path(c, a).
+path(c, d).
+path(d, d).
+path(d, c).
+path(d, b).
+path(d, a).
+
diff --git a/collects/tests/datalog/examples/says.rkt b/collects/tests/datalog/examples/says.rkt
new file mode 100644
index 0000000000..5ee12bb17a
--- /dev/null
+++ b/collects/tests/datalog/examples/says.rkt
@@ -0,0 +1,5 @@
+#lang datalog
+tpme(tpme1).
+ms(m1,'TPME',tpme1,ek,tp).
+says(TPME,M) :- tpme(TPME),ms(M,'TPME',TPME,A,B).
+says(A,B)?
diff --git a/collects/tests/datalog/examples/says.txt b/collects/tests/datalog/examples/says.txt
new file mode 100644
index 0000000000..473484aa10
--- /dev/null
+++ b/collects/tests/datalog/examples/says.txt
@@ -0,0 +1 @@
+says(tpme1, m1).
diff --git a/collects/tests/datalog/examples/true.rkt b/collects/tests/datalog/examples/true.rkt
new file mode 100644
index 0000000000..eed11d3683
--- /dev/null
+++ b/collects/tests/datalog/examples/true.rkt
@@ -0,0 +1,3 @@
+#lang datalog
+true.
+true?
diff --git a/collects/tests/datalog/examples/true.txt b/collects/tests/datalog/examples/true.txt
new file mode 100644
index 0000000000..48eb7ed1a0
--- /dev/null
+++ b/collects/tests/datalog/examples/true.txt
@@ -0,0 +1 @@
+true.
diff --git a/collects/tests/datalog/examples/tutorial.rkt b/collects/tests/datalog/examples/tutorial.rkt
new file mode 100644
index 0000000000..5981f22c80
--- /dev/null
+++ b/collects/tests/datalog/examples/tutorial.rkt
@@ -0,0 +1,42 @@
+#lang datalog
+
+parent(john,douglas).
+parent(john,douglas)?
+% parent(john, douglas).
+
+parent(john,ebbon)?
+
+parent(bob,john).
+parent(ebbon,bob).
+parent(A,B)?
+% parent(john, douglas).
+% parent(bob, john).
+% parent(ebbon, bob).
+
+parent(john,B)?
+% parent(john, douglas).
+
+parent(A,A)?
+
+ancestor(A,B) :- parent(A,B).
+ancestor(A,B) :- parent(A,C), ancestor(C, B).
+ancestor(A, B)?
+% ancestor(ebbon, bob).
+% ancestor(bob, john).
+% ancestor(john, douglas).
+% ancestor(bob, douglas).
+% ancestor(ebbon, john).
+% ancestor(ebbon, douglas).
+
+ancestor(X,john)?
+% ancestor(bob, john).
+% ancestor(ebbon, john).
+
+parent(bob, john)~
+parent(A,B)?
+% parent(john, douglas).
+% parent(ebbon, bob).
+
+ancestor(A,B)?
+% ancestor(john, douglas).
+% ancestor(ebbon, bob).
diff --git a/collects/tests/datalog/examples/tutorial.txt b/collects/tests/datalog/examples/tutorial.txt
new file mode 100644
index 0000000000..629d2dc725
--- /dev/null
+++ b/collects/tests/datalog/examples/tutorial.txt
@@ -0,0 +1,26 @@
+parent(john, douglas).
+
+
+parent(john, douglas).
+parent(bob, john).
+parent(ebbon, bob).
+
+parent(john, douglas).
+
+
+ancestor(ebbon, bob).
+ancestor(bob, john).
+ancestor(john, douglas).
+ancestor(bob, douglas).
+ancestor(ebbon, john).
+ancestor(ebbon, douglas).
+
+ancestor(bob, john).
+ancestor(ebbon, john).
+
+parent(john, douglas).
+parent(ebbon, bob).
+
+ancestor(ebbon, bob).
+ancestor(john, douglas).
+
diff --git a/collects/tests/datalog/main.rkt b/collects/tests/datalog/main.rkt
new file mode 100644
index 0000000000..739863082c
--- /dev/null
+++ b/collects/tests/datalog/main.rkt
@@ -0,0 +1,42 @@
+#lang racket
+(require rackunit
+         rackunit/text-ui
+         "ast.rkt"
+         
+         "private/lex.rkt"
+         "tool/syntax-color.rkt"
+         "parse.rkt"
+         "sexp.rkt"
+         
+         "pretty.rkt"
+         
+         "private/env.rkt"
+         "private/subst.rkt"
+         "private/unify.rkt"
+         "private/variant.rkt"
+         
+         "runtime.rkt"
+         "eval.rkt"         
+         "private/compiler.rkt")
+
+(run-tests
+ (test-suite
+  "Datalog"
+  ast-tests
+  
+  lex-tests
+  syntax-color-tests
+  parse-tests
+  sexp-tests
+  
+  pretty-tests
+  
+  env-tests
+  subst-tests
+  unify-tests
+  variant-tests
+  
+  runtime-tests
+  eval-tests
+  
+  compiler-tests))
\ No newline at end of file
diff --git a/collects/tests/datalog/paren-examples/ancestor.rkt b/collects/tests/datalog/paren-examples/ancestor.rkt
new file mode 100644
index 0000000000..78e5f87188
--- /dev/null
+++ b/collects/tests/datalog/paren-examples/ancestor.rkt
@@ -0,0 +1,12 @@
+#lang datalog/sexp
+; Equality test
+(! (:- (ancestor ,A ,B)
+       (parent ,A ,B)))
+(! (:- (ancestor ,A ,B)
+       (parent ,A ,C)
+       (= D C) ; Unification required
+       (ancestor ,D ,B)))
+(! (parent john douglas))
+(! (parent bob john))
+(! (parent ebbon bob))
+(? (ancestor ,A ,B))
diff --git a/collects/tests/datalog/paren-examples/ancestor.txt b/collects/tests/datalog/paren-examples/ancestor.txt
new file mode 100644
index 0000000000..27724bbbfb
--- /dev/null
+++ b/collects/tests/datalog/paren-examples/ancestor.txt
@@ -0,0 +1,6 @@
+ancestor(ebbon, douglas).
+ancestor(ebbon, john).
+ancestor(bob, douglas).
+ancestor(ebbon, bob).
+ancestor(bob, john).
+ancestor(john, douglas).
diff --git a/collects/tests/datalog/paren-examples/bidipath.rkt b/collects/tests/datalog/paren-examples/bidipath.rkt
new file mode 100644
index 0000000000..9582561db7
--- /dev/null
+++ b/collects/tests/datalog/paren-examples/bidipath.rkt
@@ -0,0 +1,15 @@
+#lang datalog/sexp
+; path test from Chen & Warren
+(! (edge a b))
+(! (edge b c))
+(! (edge c d))
+(! (edge d a))
+(! (:- (path ,X ,Y)
+       (edge ,X ,Y)))
+(! (:- (path ,X ,Y)
+       (edge ,X ,Z)
+       (path ,Z ,Y)))
+(! (:- (path ,X ,Y)
+       (path ,X ,Z)
+       (edge ,Z ,Y)))
+(? (path ,X ,Y))
\ No newline at end of file
diff --git a/collects/tests/datalog/paren-examples/bidipath.txt b/collects/tests/datalog/paren-examples/bidipath.txt
new file mode 100644
index 0000000000..6c197dd6eb
--- /dev/null
+++ b/collects/tests/datalog/paren-examples/bidipath.txt
@@ -0,0 +1,17 @@
+path(a, a).
+path(a, d).
+path(a, c).
+path(a, b).
+path(b, b).
+path(b, a).
+path(b, d).
+path(b, c).
+path(c, c).
+path(c, b).
+path(c, a).
+path(c, d).
+path(d, d).
+path(d, c).
+path(d, b).
+path(d, a).
+
diff --git a/collects/tests/datalog/paren-examples/laps.rkt b/collects/tests/datalog/paren-examples/laps.rkt
new file mode 100644
index 0000000000..4bf83043e9
--- /dev/null
+++ b/collects/tests/datalog/paren-examples/laps.rkt
@@ -0,0 +1,13 @@
+#lang datalog/sexp
+; Laps Test
+(! (contains ca store rams_couch rams))
+(! (contains rams fetch rams_couch will))
+(! (:- (contains ca fetch ,Name ,Watcher)
+       (contains ca store ,Name ,Owner)
+       (contains ,Owner fetch ,Name ,Watcher)))
+(! (trusted ca))
+(! (:- (permit ,User ,Priv ,Name)
+       (contains ,Auth ,Priv ,Name ,User)
+       (trusted ,Auth)))
+(? (permit ,User ,Priv ,Name))
+
diff --git a/collects/tests/datalog/paren-examples/laps.txt b/collects/tests/datalog/paren-examples/laps.txt
new file mode 100644
index 0000000000..d87ea5fb54
--- /dev/null
+++ b/collects/tests/datalog/paren-examples/laps.txt
@@ -0,0 +1,2 @@
+permit(rams, store, rams_couch).
+permit(will, fetch, rams_couch).
diff --git a/collects/tests/datalog/paren-examples/long.rkt b/collects/tests/datalog/paren-examples/long.rkt
new file mode 100644
index 0000000000..ad6ef3d758
--- /dev/null
+++ b/collects/tests/datalog/paren-examples/long.rkt
@@ -0,0 +1,8 @@
+#lang datalog/sexp
+(! (abcdefghi z123456789
+              z1234567890123456789
+              z123456789012345678901234567890123456789
+              z1234567890123456789012345678901234567890123456789012345678901234567890123456789))
+(! this_is_a_long_identifier_and_tests_the_scanners_concat_when_read_with_a_small_buffer)
+(? this_is_a_long_identifier_and_tests_the_scanners_concat_when_read_with_a_small_buffer)
+
diff --git a/collects/tests/datalog/paren-examples/long.txt b/collects/tests/datalog/paren-examples/long.txt
new file mode 100644
index 0000000000..ebf5669da9
--- /dev/null
+++ b/collects/tests/datalog/paren-examples/long.txt
@@ -0,0 +1 @@
+this_is_a_long_identifier_and_tests_the_scanners_concat_when_read_with_a_small_buffer.
diff --git a/collects/tests/datalog/paren-examples/path.rkt b/collects/tests/datalog/paren-examples/path.rkt
new file mode 100644
index 0000000000..31de89cb29
--- /dev/null
+++ b/collects/tests/datalog/paren-examples/path.rkt
@@ -0,0 +1,12 @@
+#lang datalog/sexp
+; path test from Chen & Warren
+(! (edge a b))
+(! (edge b c))
+(! (edge c d))
+(! (edge d a))
+(! (:- (path ,X ,Y)
+       (edge ,X ,Y)))
+(! (:- (path ,X ,Y)
+       (edge ,X ,Z)
+       (path ,Z ,Y)))
+(? (path ,X ,Y))
diff --git a/collects/tests/datalog/paren-examples/path.txt b/collects/tests/datalog/paren-examples/path.txt
new file mode 100644
index 0000000000..cfe9daed0a
--- /dev/null
+++ b/collects/tests/datalog/paren-examples/path.txt
@@ -0,0 +1,17 @@
+path(a, a).
+path(a, d).
+path(a, c).
+path(a, b).
+path(b, a).
+path(b, d).
+path(b, c).
+path(b, b).
+path(c, a).
+path(c, b).
+path(c, c).
+path(c, d).
+path(d, b).
+path(d, c).
+path(d, d).
+path(d, a).
+
diff --git a/collects/tests/datalog/paren-examples/pq.rkt b/collects/tests/datalog/paren-examples/pq.rkt
new file mode 100644
index 0000000000..1c08e17f80
--- /dev/null
+++ b/collects/tests/datalog/paren-examples/pq.rkt
@@ -0,0 +1,8 @@
+#lang datalog/sexp
+; p q test from Chen & Warren
+(! (:- (q ,X)
+       (p ,X)))
+(! (q a))
+(! (:- (p ,X)
+       (q ,X)))
+(? (q ,X))
diff --git a/collects/tests/datalog/paren-examples/pq.txt b/collects/tests/datalog/paren-examples/pq.txt
new file mode 100644
index 0000000000..7526e512b1
--- /dev/null
+++ b/collects/tests/datalog/paren-examples/pq.txt
@@ -0,0 +1 @@
+q(a).
diff --git a/collects/tests/datalog/paren-examples/revpath.rkt b/collects/tests/datalog/paren-examples/revpath.rkt
new file mode 100644
index 0000000000..33cc2385ab
--- /dev/null
+++ b/collects/tests/datalog/paren-examples/revpath.rkt
@@ -0,0 +1,12 @@
+#lang datalog/sexp
+; path test from Chen & Warren
+(! (edge a b))
+(! (edge b c))
+(! (edge c d))
+(! (edge d a))
+(! (:- (path ,X ,Y)
+       (edge ,X ,Y)))
+(! (:- (path ,X ,Y)
+       (path ,X ,Z)
+       (edge ,Z ,Y)))
+(? (path ,X ,Y))
\ No newline at end of file
diff --git a/collects/tests/datalog/paren-examples/revpath.txt b/collects/tests/datalog/paren-examples/revpath.txt
new file mode 100644
index 0000000000..6c197dd6eb
--- /dev/null
+++ b/collects/tests/datalog/paren-examples/revpath.txt
@@ -0,0 +1,17 @@
+path(a, a).
+path(a, d).
+path(a, c).
+path(a, b).
+path(b, b).
+path(b, a).
+path(b, d).
+path(b, c).
+path(c, c).
+path(c, b).
+path(c, a).
+path(c, d).
+path(d, d).
+path(d, c).
+path(d, b).
+path(d, a).
+
diff --git a/collects/tests/datalog/paren-examples/says.rkt b/collects/tests/datalog/paren-examples/says.rkt
new file mode 100644
index 0000000000..1c10fb071a
--- /dev/null
+++ b/collects/tests/datalog/paren-examples/says.rkt
@@ -0,0 +1,7 @@
+#lang datalog/sexp
+(! (tpme tpme1))
+(! (ms m1 "TPME" tpme1 ek tp))
+(! (:- (says ,TPME ,M)
+       (tpme ,TPME)
+       (ms ,M "TPME" ,TPME ,A ,B)))
+(? (says ,A ,B))
diff --git a/collects/tests/datalog/paren-examples/says.txt b/collects/tests/datalog/paren-examples/says.txt
new file mode 100644
index 0000000000..473484aa10
--- /dev/null
+++ b/collects/tests/datalog/paren-examples/says.txt
@@ -0,0 +1 @@
+says(tpme1, m1).
diff --git a/collects/tests/datalog/paren-examples/true.rkt b/collects/tests/datalog/paren-examples/true.rkt
new file mode 100644
index 0000000000..18ccecb939
--- /dev/null
+++ b/collects/tests/datalog/paren-examples/true.rkt
@@ -0,0 +1,3 @@
+#lang datalog/sexp
+(! true)
+(? true)
\ No newline at end of file
diff --git a/collects/tests/datalog/paren-examples/true.txt b/collects/tests/datalog/paren-examples/true.txt
new file mode 100644
index 0000000000..48eb7ed1a0
--- /dev/null
+++ b/collects/tests/datalog/paren-examples/true.txt
@@ -0,0 +1 @@
+true.
diff --git a/collects/tests/datalog/paren-examples/tutorial.rkt b/collects/tests/datalog/paren-examples/tutorial.rkt
new file mode 100644
index 0000000000..90e1d6cc22
--- /dev/null
+++ b/collects/tests/datalog/paren-examples/tutorial.rkt
@@ -0,0 +1,28 @@
+#lang datalog/sexp
+(! (parent john douglas))
+(? (parent john douglas))
+
+(? (parent john ebbon))
+
+(! (parent bob john))
+(! (parent ebbon bob))
+(? (parent ,A ,B))
+
+(? (parent john ,B))
+
+(? (parent ,A ,A))
+
+(! (:- (ancestor ,A ,B)
+       (parent ,A ,B)))
+(! (:- (ancestor ,A ,B)
+       (parent ,A ,C)
+       (ancestor ,C ,B)))
+(? (ancestor ,A ,B))
+
+(? (ancestor ,X john))
+
+(~ (parent bob john))
+
+(? (parent ,A ,B))
+
+(? (ancestor ,A ,B))
diff --git a/collects/tests/datalog/paren-examples/tutorial.txt b/collects/tests/datalog/paren-examples/tutorial.txt
new file mode 100644
index 0000000000..629d2dc725
--- /dev/null
+++ b/collects/tests/datalog/paren-examples/tutorial.txt
@@ -0,0 +1,26 @@
+parent(john, douglas).
+
+
+parent(john, douglas).
+parent(bob, john).
+parent(ebbon, bob).
+
+parent(john, douglas).
+
+
+ancestor(ebbon, bob).
+ancestor(bob, john).
+ancestor(john, douglas).
+ancestor(bob, douglas).
+ancestor(ebbon, john).
+ancestor(ebbon, douglas).
+
+ancestor(bob, john).
+ancestor(ebbon, john).
+
+parent(john, douglas).
+parent(ebbon, bob).
+
+ancestor(ebbon, bob).
+ancestor(john, douglas).
+
diff --git a/collects/tests/datalog/parse.rkt b/collects/tests/datalog/parse.rkt
new file mode 100644
index 0000000000..db86b57ecc
--- /dev/null
+++ b/collects/tests/datalog/parse.rkt
@@ -0,0 +1,52 @@
+#lang racket
+(require rackunit
+         datalog/ast
+         datalog/parse
+         "util.rkt")
+
+(provide parse-tests)
+
+(define (test-literal-parse str res)
+  (test-literal str (parse-literal (open-input-string str)) res))
+(define (test-clause-parse str res)
+  (test-clause str (parse-clause (open-input-string str)) res))
+
+(define parse-tests
+  (test-suite
+   "parse"
+   
+   (test-suite
+    "literal"
+    (test-literal-parse "parent(john, douglas)"
+                        (make-literal #f 'parent (list (make-constant #f 'john) (make-constant #f 'douglas))))
+    (test-literal-parse "1 = 2"
+                        (make-literal #f '= (list (make-constant #f '|1|) (make-constant #f '|2|))))
+    (test-literal-parse "zero-arity-literal"
+                        (make-literal #f 'zero-arity-literal empty))
+    (test-literal-parse "zero-arity-literal()"
+                        (make-literal #f 'zero-arity-literal empty))
+    (test-literal-parse "\"=\"(3,3)"
+                        (make-literal #f "=" (list (make-constant #f '|3|) (make-constant #f '|3|))))
+    (test-literal-parse "\"\"(-0-0-0,&&&,***,\"\00\")"
+                        (make-literal #f "" (list (make-constant #f '-0-0-0)
+                                                  (make-constant #f '&&&)
+                                                  (make-constant #f '***)
+                                                  (make-constant #f "\00")))))
+   
+   (test-suite
+    "clause"
+    (test-clause-parse "parent(john, douglas)"
+                       (make-clause #f (make-literal #f 'parent (list (make-constant #f 'john) (make-constant #f 'douglas))) empty))
+    (test-clause-parse "ancestor(A, B) :- parent(A, B)"
+                       (make-clause #f (make-literal #f 'ancestor (list (make-variable #f 'A) (make-variable #f 'B)))
+                                    (list (make-literal #f 'parent (list (make-variable #f 'A) (make-variable #f 'B))))))
+    (test-clause-parse "ancestor(A, B) :- parent(A, C), ancestor(C, B)"
+                       (make-clause #f (make-literal #f 'ancestor (list (make-variable #f 'A) (make-variable #f 'B)))
+                                    (list (make-literal #f 'parent (list (make-variable #f 'A) (make-variable #f 'C)))
+                                          (make-literal #f 'ancestor (list (make-variable #f 'C) (make-variable #f 'B)))))))
+   
+   (test-suite
+    "statement"
+    (test-not-false "assertion" (assertion? (parse-statement (open-input-string "parent(john, douglas)."))))
+    (test-not-false "retraction" (retraction? (parse-statement (open-input-string "parent(john, douglas)~"))))
+    (test-not-false "query" (query? (parse-statement (open-input-string "parent(john, douglas)?")))))))
\ No newline at end of file
diff --git a/collects/tests/datalog/pretty.rkt b/collects/tests/datalog/pretty.rkt
new file mode 100644
index 0000000000..a0fe3392bc
--- /dev/null
+++ b/collects/tests/datalog/pretty.rkt
@@ -0,0 +1,49 @@
+#lang racket
+(require rackunit
+         datalog/parse
+         datalog/pretty)
+(provide pretty-tests)
+
+(define pretty-tests
+  (test-suite
+   "Pretty"
+   
+   (test-equal? "program"
+ (format-program
+  (parse-program
+   (open-input-string #<<END
+parent(john, douglas).
+parent(john, douglas)?
+parent(john, ebbon)?
+parent(bob, john).
+parent(ebbon, bob).
+parent(A, B)?
+parent(john, B)?
+parent(A, A)?
+ancestor(A, B) :- parent(A, B).
+ancestor(A, B) :- 
+ parent(A, C),
+ ancestor(C, B).
+ancestor(A, B)?
+parent(bob, john)~
+parent(A,B)?
+ancestor(A,B)?
+END
+                      )))
+                #<<END
+parent(john, douglas).
+parent(john, douglas)?
+parent(john, ebbon)?
+parent(bob, john).
+parent(ebbon, bob).
+parent(A, B)?
+parent(john, B)?
+parent(A, A)?
+ancestor(A, B) :- parent(A, B).
+ancestor(A, B) :- parent(A, C), ancestor(C, B).
+ancestor(A, B)?
+parent(bob, john)~
+parent(A, B)?
+ancestor(A, B)?
+END
+                )))
\ No newline at end of file
diff --git a/collects/tests/datalog/private/compiler.rkt b/collects/tests/datalog/private/compiler.rkt
new file mode 100644
index 0000000000..74cc1c653c
--- /dev/null
+++ b/collects/tests/datalog/private/compiler.rkt
@@ -0,0 +1,24 @@
+#lang racket
+(require rackunit
+         (for-template datalog/eval)
+         datalog/parse
+         datalog/private/compiler)
+
+(provide compiler-tests)
+
+(define s1
+  (parse-statement
+   (open-input-string
+    "parent(john,douglas).")))
+  
+(define compiler-tests
+  (test-suite
+   "compiler"
+   
+   (test-equal? "stmt"
+                (syntax->datum (compile-stmt s1))
+                `(eval-statement ,s1))
+   (test-equal? "module"
+                (syntax->datum (compile-module (list s1)))
+                `(begin (eval-statement ,s1)))))
+   
\ No newline at end of file
diff --git a/collects/tests/datalog/private/env.rkt b/collects/tests/datalog/private/env.rkt
new file mode 100644
index 0000000000..c9f5ad2707
--- /dev/null
+++ b/collects/tests/datalog/private/env.rkt
@@ -0,0 +1,22 @@
+#lang racket
+(require rackunit
+         datalog/ast
+         datalog/private/env)
+
+(provide env-tests)
+
+(define t1 (make-constant #f 't1))
+(define t2 (make-constant #f 't2))
+
+(define env-tests
+  (test-suite
+   "env"
+   
+   (test-equal? "default" (lookup (empty-env) 'v) #f)
+   (test-equal? "default" (lookup (empty-env) 'v t1) t1)
+   (test-equal? "extend" (lookup (extend (empty-env) 'v1 t1) 'v1) t1)
+   (test-equal? "extend"
+                (lookup (extend (extend (empty-env) 'v1 t1)
+                                'v1 t1)
+                        'v1)
+                t1)))
\ No newline at end of file
diff --git a/collects/tests/datalog/private/lex.rkt b/collects/tests/datalog/private/lex.rkt
new file mode 100644
index 0000000000..6648cfd378
--- /dev/null
+++ b/collects/tests/datalog/private/lex.rkt
@@ -0,0 +1,37 @@
+#lang racket
+(require rackunit
+         parser-tools/lex
+         datalog/private/lex)
+
+(provide lex-tests)
+
+(define (test-lexer str tok-name [tok-value str])
+  (define pv (dlexer (open-input-string str)))
+  (define v (position-token-token pv))
+  (test-equal? (format "lexer: ~a: <~a,~a>" str tok-name tok-value)
+               (cons tok-name tok-value)
+               (cons (token-name v) (token-value v))))
+
+(define lex-tests
+  (test-suite
+   "lex"
+   
+   (test-lexer "=" 'EQUAL #f)
+   (test-lexer "?" 'QMARK #f)
+   (test-lexer "~" 'TILDE #f)
+   (test-lexer "." 'DOT #f)
+   (test-lexer ")" 'RPAREN #f)
+   (test-lexer "," 'COMMA #f)
+   (test-lexer "(" 'LPAREN #f)
+   (test-lexer "\"\"" 'STRING "")
+   (test-lexer "\"foo\"" 'STRING "foo")
+   (test-lexer "\"\\\"\"" 'STRING "\"")
+   (test-lexer ":-" 'TSTILE #f)
+   (test-lexer "" 'EOF #f)
+   (test-lexer "Va1_" 'VARIABLE)
+   (test-lexer "val_" 'IDENTIFIER)
+   (test-lexer "912Kadf" 'IDENTIFIER)
+   (test-lexer "    =" 'EQUAL #f)
+   (test-lexer "% 12453\n=" 'EQUAL #f)
+   
+   ))
\ No newline at end of file
diff --git a/collects/tests/datalog/private/subst.rkt b/collects/tests/datalog/private/subst.rkt
new file mode 100644
index 0000000000..2871f40eb7
--- /dev/null
+++ b/collects/tests/datalog/private/subst.rkt
@@ -0,0 +1,114 @@
+#lang racket
+(require rackunit
+         datalog/private/subst
+         datalog/ast
+         datalog/private/env)
+(require/expose datalog/private/subst (subst-literal shuffle))
+
+(provide subst-tests)
+
+(define (gensym-var? v)
+  (define s (variable-sym v))
+  (not (eq? s (string->symbol (symbol->string s)))))
+
+(define subst-tests
+  (test-suite
+   "subst"
+   
+   (test-suite
+    "subst-term"
+    (test-equal? "con" 
+                 (subst-term (empty-env) (make-constant #f 'v1))
+                 (make-constant #f 'v1))
+    (test-equal? "var def" 
+                 (subst-term (empty-env) (make-variable #f 'v1))
+                 (make-variable #f 'v1))
+    (test-equal? "var" 
+                 (subst-term (extend (empty-env) 'v1 (make-constant #f 'v1)) (make-variable #f 'v1))
+                 (make-constant #f 'v1)))
+   
+   (test-suite
+    "subst-literal"
+    (test-equal? "con"
+                 (subst-literal (empty-env) (make-literal #f 'lit (list (make-constant #f 'v1))))
+                 (make-literal #f 'lit (list (make-constant #f 'v1))))
+    (test-equal? "var def"
+                 (subst-literal (extend (empty-env) 'v1 (make-constant #f 'v1)) (make-literal #f 'lit (list (make-variable #f 'v1))))
+                 (make-literal #f 'lit (list (make-constant #f 'v1))))
+    (test-equal? "var def"
+                 (subst-literal (extend (empty-env) 'v1 (make-constant #f 'v1)) (make-literal #f 'lit (list (make-variable #f 'v1))))
+                 (make-literal #f 'lit (list (make-constant #f 'v1)))))
+   
+   (test-suite
+    "subst-clause"
+    (test-equal? "con"
+                 (subst-clause (empty-env) (make-clause #f (make-literal #f 'lit (list (make-constant #f 'v1))) empty))
+                 (make-clause #f (make-literal #f 'lit (list (make-constant #f 'v1))) empty))
+    (test-equal? "var def"
+                 (subst-clause (extend (empty-env) 'v1 (make-constant #f 'v1)) 
+                               (make-clause #f (make-literal #f 'lit (list (make-variable #f 'v1))) empty))
+                 (make-clause #f (make-literal #f 'lit (list (make-constant #f 'v1))) empty))
+    (test-equal? "var def"
+                 (subst-clause (extend (empty-env) 'v1 (make-constant #f 'v1)) 
+                               (make-clause #f (make-literal #f 'lit (list (make-variable #f 'v1))) empty))
+                 (make-clause #f (make-literal #f 'lit (list (make-constant #f 'v1))) empty))
+    
+    (test-equal? "con"
+                 (subst-clause (empty-env) (make-clause #f (make-literal #f 'lit (list (make-constant #f 'v1))) 
+                                                        (list (make-literal #f 'lit (list (make-constant #f 'v1))))))
+                 (make-clause #f (make-literal #f 'lit (list (make-constant #f 'v1)))
+                              (list (make-literal #f 'lit (list (make-constant #f 'v1))))))
+    (test-equal? "var def"
+                 (subst-clause (extend (empty-env) 'v1 (make-constant #f 'v1)) 
+                               (make-clause #f (make-literal #f 'lit (list (make-variable #f 'v1))) 
+                                            (list (make-literal #f 'lit (list (make-variable #f 'v1))))))
+                 (make-clause #f (make-literal #f 'lit (list (make-constant #f 'v1)))
+                              (list (make-literal #f 'lit (list (make-constant #f 'v1))))))
+    (test-equal? "var def"
+                 (subst-clause (extend (empty-env) 'v1 (make-constant #f 'v1)) 
+                               (make-clause #f (make-literal #f 'lit (list (make-variable #f 'v1)))
+                                            (list (make-literal #f 'lit (list (make-variable #f 'v1))))))
+                 (make-clause #f (make-literal #f 'lit (list (make-constant #f 'v1)))
+                              (list (make-literal #f 'lit (list (make-constant #f 'v1)))))))
+   
+   (test-suite
+    "shuffle"
+    (test-equal? "con" 
+                 (shuffle (empty-env) (make-literal #f 'lit (list (make-constant #f 'v1))))
+                 (empty-env))
+    (test-equal? "var" 
+                 (shuffle (extend (empty-env) 'v1 (make-constant #f 'k1)) (make-literal #f 'lit (list (make-variable #f 'v1))))
+                 (extend (empty-env) 'v1 (make-constant #f 'k1)))
+    (test-not-false "var"
+                    (gensym-var? (lookup (shuffle (empty-env)
+                                                  (make-literal #f 'lit (list (make-variable #f 'v1))))
+                                         'v1))))
+   
+   (test-suite
+    "rename-literal"
+    (test-equal? "l" (rename-literal (make-literal #f 'lit (list (make-constant #f 'v1))))
+                 (make-literal #f 'lit (list (make-constant #f 'v1))))
+    (test-not-false "l"
+                    (gensym-var?
+                     (first
+                      (literal-terms
+                       (rename-literal (make-literal #f 'lit (list (make-variable #f 'v1)))))))))
+   
+   (test-suite
+    "rename-clause"
+    (test-equal? "c" (rename-clause (make-clause #f (make-literal #f 'lit (list (make-constant #f 'v1))) empty))
+                 (make-clause #f (make-literal #f 'lit (list (make-constant #f 'v1))) empty))
+    (test-not-false "c"
+                    (gensym-var? 
+                     (first
+                      (literal-terms
+                       (clause-head 
+                        (rename-clause (make-clause #f (make-literal #f 'lit (list (make-variable #f 'v1))) empty)))))))
+    (test-not-false "c"
+                    (gensym-var? 
+                     (first
+                      (literal-terms
+                       (first
+                        (clause-body
+                         (rename-clause (make-clause #f (make-literal #f 'lit (list (make-constant #f 'v1)))
+                                                     (list (make-literal #f 'lit (list (make-variable #f 'v1)))))))))))))))
\ No newline at end of file
diff --git a/collects/tests/datalog/private/unify.rkt b/collects/tests/datalog/private/unify.rkt
new file mode 100644
index 0000000000..2ea94e61a5
--- /dev/null
+++ b/collects/tests/datalog/private/unify.rkt
@@ -0,0 +1,54 @@
+#lang racket
+(require rackunit
+         datalog/ast
+         datalog/private/env
+         datalog/private/unify)
+(require/expose datalog/private/unify (chase unify-terms))
+
+(provide unify-tests)
+
+(define unify-tests
+  (test-suite
+   "unify"
+   
+   (test-suite
+    "chase"
+    (test-equal? "con" (chase (empty-env) (make-constant #f 'k1))
+                 (make-constant #f 'k1))
+    (test-equal? "var" (chase (empty-env) (make-variable #f 'v1))
+                 (make-variable #f 'v1))
+    (test-equal? "var->con"
+                 (chase (extend (empty-env) 'v1 (make-constant #f 'k1)) (make-variable #f 'v1))
+                 (make-constant #f 'k1))
+    (test-equal? "var->var->con"
+                 (chase (extend (extend (empty-env) 'v2 (make-constant #f 'k1))
+                                'v1 (make-variable #f 'v2))
+                        (make-variable #f 'v1))
+                 (make-constant #f 'k1)))
+   
+   (test-suite
+    "unify-term"
+    (test-equal? "con/con" (unify-term (empty-env) (make-constant #f 'k1) (make-constant #f 'k1))
+                 (empty-env))
+    (test-false "con/con" (unify-term (empty-env) (make-constant #f 'k1) (make-constant #f 'k2)))
+    (test-equal? "var/con" (unify-term (empty-env) (make-variable #f 'v1) (make-constant #f 'k2))
+                 (extend (empty-env) 'v1 (make-constant #f 'k2)))
+    (test-equal? "con/var" (unify-term (empty-env) (make-constant #f 'k2) (make-variable #f 'v1))
+                 (extend (empty-env) 'v1 (make-constant #f 'k2)))
+    (test-equal? "var/var" (unify-term (empty-env) (make-variable #f 'v1) (make-variable #f 'v2))
+                 (extend (empty-env) 'v1 (make-variable #f 'v2))))
+   
+   (test-suite
+    "unify-terms"
+    (test-equal? "con/con" (unify-terms (empty-env) (list (make-constant #f 'k1)) (list (make-constant #f 'k1)))
+                 (empty-env))
+    (test-false "con/con" (unify-terms (empty-env) (list (make-constant #f 'k1)) (list (make-constant #f 'k2))))
+    (test-false "/con" (unify-terms (empty-env) (list) (list (make-constant #f 'k2))))
+    (test-false "con/" (unify-terms (empty-env) (list (make-constant #f 'k2)) (list))))
+   
+   (test-suite
+    "unify"
+    (test-false "lit/lit" (unify (make-literal #f 'lit1 empty) (make-literal #f 'lit2 empty)))
+    (test-equal? "con/con" (unify (make-literal #f 'lit1 (list (make-constant #f 'k1)))
+                                  (make-literal #f 'lit1 (list (make-constant #f 'k1))))
+                 (empty-env)))))
\ No newline at end of file
diff --git a/collects/tests/datalog/private/variant.rkt b/collects/tests/datalog/private/variant.rkt
new file mode 100644
index 0000000000..cd1299b62b
--- /dev/null
+++ b/collects/tests/datalog/private/variant.rkt
@@ -0,0 +1,59 @@
+#lang racket
+(require rackunit
+         datalog/ast
+         datalog/private/variant)
+(require/expose datalog/private/variant
+                (variant-terms variant-term variant-var variant? term-hash mk-literal-hash))
+
+(provide variant-tests)
+
+(define (test-not-equal? n v1 v2)
+  (test-case n (check-not-equal? v1 v2)))
+
+(define variant-tests
+  (test-suite
+   "variant"
+   
+   (test-suite 
+    "variant?"
+    (test-not-false "same" (variant? (make-literal #f 'lit1 empty) (make-literal #f 'lit1 empty)))
+    (test-false "dif lit" (variant? (make-literal #f 'lit1 empty) (make-literal #f 'lit2 empty)))
+    (test-not-false "same" (variant? (make-literal #f 'lit1 (list (make-constant #f 'k1))) 
+                                     (make-literal #f 'lit1 (list (make-constant #f 'k1)))))
+    (test-false "dif con" (variant? (make-literal #f 'lit1 (list (make-constant #f 'k1))) 
+                                    (make-literal #f 'lit1 (list (make-constant #f 'k2)))))
+    (test-false "dif var/con" (variant? (make-literal #f 'lit1 (list (make-variable #f 'v1))) 
+                                        (make-literal #f 'lit1 (list (make-constant #f 'k1)))))
+    (test-false "dif con/var" (variant? (make-literal #f 'lit1 (list (make-constant #f 'k1))) 
+                                        (make-literal #f 'lit1 (list (make-variable #f 'v1)))))
+    (test-not-false "same" (variant? (make-literal #f 'lit1 (list (make-variable #f 'v1))) 
+                                     (make-literal #f 'lit1 (list (make-variable #f 'v1)))))
+    
+    (test-not-false "var (dif name)" (variant? (make-literal #f 'lit1 (list (make-variable #f 'v2))) 
+                                               (make-literal #f 'lit1 (list (make-variable #f 'v1))))))
+   
+   (test-suite
+    "mem-literal"
+    (test-false "mt" (mem-literal (make-literal #f 'lit1 empty) empty))
+    (test-not-false "in" (mem-literal (make-literal #f 'lit1 empty) (list (make-literal #f 'lit1 empty))))
+    (test-not-false "var" (mem-literal (make-literal #f 'lit1 (list (make-variable #f 'v2))) 
+                                       (list (make-literal #f 'lit1 (list (make-variable #f 'v1)))))))
+   
+   (test-suite
+    "term-hash"
+    (test-equal? "var" (term-hash (make-variable #f (gensym)) equal-hash-code) 101)
+    (test-equal? "con" (term-hash (make-constant #f 'v2) equal-hash-code) (equal-hash-code 'v2)))
+   
+   (local [(define literal-hash (mk-literal-hash equal-hash-code))
+           (define (literal-hash-equal? l1 l2)
+             (equal? (literal-hash l1) (literal-hash l2)))]
+     (test-suite
+      "mk-literal-hash"
+      (test-not-false "same" (literal-hash-equal? (make-literal #f 'lit1 empty) (make-literal #f 'lit1 empty)))
+      (test-not-false "same" (literal-hash-equal? (make-literal #f 'lit1 (list (make-constant #f 'k1))) 
+                                                  (make-literal #f 'lit1 (list (make-constant #f 'k1)))))
+      (test-not-false "same" (literal-hash-equal? (make-literal #f 'lit1 (list (make-variable #f 'v1))) 
+                                                  (make-literal #f 'lit1 (list (make-variable #f 'v1)))))
+      
+      (test-not-false "var (dif name)" (literal-hash-equal? (make-literal #f 'lit1 (list (make-variable #f 'v2))) 
+                                                            (make-literal #f 'lit1 (list (make-variable #f 'v1)))))))))
\ No newline at end of file
diff --git a/collects/tests/datalog/runtime.rkt b/collects/tests/datalog/runtime.rkt
new file mode 100644
index 0000000000..202f8ffac6
--- /dev/null
+++ b/collects/tests/datalog/runtime.rkt
@@ -0,0 +1,53 @@
+#lang racket
+(require rackunit
+         datalog/parse
+         datalog/runtime
+         "util.rkt")
+
+(provide runtime-tests)
+
+(define pc (parse-clause (open-input-string "parent(john, douglas)")))
+(define pl (parse-literal (open-input-string "parent(john, douglas)")))
+
+(define runtime-tests
+  (test-suite
+   "runtime"
+   
+   (test-suite
+    "safe-clause?"
+    (test-not-false "safe" (safe-clause? pc))
+    (test-not-false "safe" (safe-clause? (parse-clause (open-input-string "ancestor(A, B) :- parent(A, B)"))))
+    (test-false "not safe" (safe-clause? (parse-clause (open-input-string "ancestor(A, B) :- parent(jay, B)"))))
+    (test-not-false "safe" (safe-clause? (parse-clause (open-input-string "ancestor(A, B) :- parent(A, C), ancestor(C, B)")))))
+   
+   (test-suite
+    "imm simple"
+    (test-equal? "empty" (prove (make-immutable-theory) pl) empty)
+    (test-literal "ass->prov" 
+                  (first (prove (assume (make-immutable-theory) pc) pl))
+                  pl)
+    (test-equal? "ass->ret->prov" (prove (retract (assume (make-immutable-theory) pc) pc) pl) empty)
+    (test-equal? "ret->prov" (prove (retract (make-immutable-theory) pc) pl) empty))
+   
+   (test-suite
+    "mut simple"
+    (test-equal? "empty" (prove (make-mutable-theory) pl) empty)
+    (test-literal "ass->prov" 
+                  (let ([thy (make-mutable-theory)])
+                    (assume! thy pc)
+                    (first (prove thy pl)))
+                  pl)
+    (test-equal? "ass->ret->prov" 
+                 (let ([thy (make-mutable-theory)])
+                   (assume! thy pc)
+                   (retract! thy pc)
+                   (prove thy pl))
+                 empty)
+    (test-equal? "ret->prov" 
+                 (let ([thy (make-mutable-theory)])
+                   (retract! thy pc)
+                   (prove thy pl))
+                 empty))
+   
+   ))
+
diff --git a/collects/tests/datalog/sexp.rkt b/collects/tests/datalog/sexp.rkt
new file mode 100644
index 0000000000..8a027b442a
--- /dev/null
+++ b/collects/tests/datalog/sexp.rkt
@@ -0,0 +1,49 @@
+#lang racket
+(require rackunit
+         datalog/ast
+         datalog/sexp
+         "util.rkt")
+
+(provide sexp-tests)
+
+(define test
+  #'(begin
+      (! (parent john douglas))
+      (? (parent john douglas))
+      (? (parent john ebbon))
+      (! (parent bob john))
+      (! (parent ebbon bob))
+      (? (parent ,A ,B))
+      (? (parent john ,B))
+      (? (parent ,A ,A))
+      (! (:- (ancestor ,A ,B)
+             (parent ,A ,B)))
+      (! (:- (ancestor ,A ,B)
+             (parent ,A ,C)
+             (ancestor ,C ,B)))
+      (? (ancestor ,A ,B))
+      (? (ancestor ,X john))
+      (~ (parent bob john))
+      (? (parent ,A ,B))
+      (? (ancestor ,A ,B))))
+
+(define sexp-tests
+  (test-suite
+   "sexp"
+   
+   (test-not-exn "program" (lambda () (contract program/c (stx->program test) 'pos 'neg)))
+   
+   (test-not-false "stmt" (assertion? (stx->statement #'(! (parent john douglas)))))
+   (test-not-false "stmt" (retraction? (stx->statement #'(~ (parent john douglas)))))
+   (test-not-false "stmt" (query? (stx->statement #'(? (parent john douglas)))))
+   
+   (test-clause "clause" (stx->clause #'(parent john douglas))
+                (make-clause #f (make-literal #f 'parent (list (make-constant #f 'john) (make-constant #f 'douglas))) empty))
+   (test-clause "clause" (stx->clause #'(:- (ancestor ,A ,B) (parent ,A ,B)))
+                (make-clause #f (make-literal #f 'ancestor (list (make-variable #f 'A) (make-variable #f 'B)))
+                             (list (make-literal #f 'parent (list (make-variable #f 'A) (make-variable #f 'B))))))
+   
+   (test-literal "literal" (stx->literal #'(parent john douglas))
+                 (make-literal #f 'parent (list (make-constant #f 'john) (make-constant #f 'douglas))))
+   
+   ))
\ No newline at end of file
diff --git a/collects/tests/datalog/tool/syntax-color.rkt b/collects/tests/datalog/tool/syntax-color.rkt
new file mode 100644
index 0000000000..6b48bb8e4e
--- /dev/null
+++ b/collects/tests/datalog/tool/syntax-color.rkt
@@ -0,0 +1,37 @@
+#lang racket
+(require rackunit
+         datalog/tool/syntax-color)
+
+(provide syntax-color-tests)
+
+(define (test-color str key)
+  (define-values (lex color b start end) (get-syntax-token (open-input-string str)))
+  (test-equal? (format "Syntax Color: ~a: ~a" key str) color key))
+
+(define syntax-color-tests
+  (test-suite
+   "syntax-color"
+   
+   (test-color " " 'whitespace)
+   (test-color "   " 'whitespace)
+   (test-color "\t" 'whitespace)
+   (test-color "\n" 'whitespace)
+   (test-color "% \n" 'comment)
+   (test-color "% 12 31 2 6\n" 'comment)
+   (test-color "Var" 'symbol)
+   (test-color "V124_3" 'symbol)
+   (test-color "var" 'identifier)
+   (test-color "123var" 'identifier)
+   (test-color "(" 'parenthesis)
+   (test-color ")" 'parenthesis)
+   (test-color "=" 'parenthesis)
+   (test-color "?" 'parenthesis)
+   (test-color "~" 'parenthesis)
+   (test-color "." 'parenthesis)
+   (test-color "," 'parenthesis)
+   (test-color ":-" 'parenthesis)
+   (test-color "\"foo\"" 'string)
+   (test-color "\"fo\\\"o\"" 'string)
+   (test-color "\"fo\no\"" 'string)
+   (test-color "\"foo" 'error)
+   (test-color ":" 'error)))
\ No newline at end of file
diff --git a/collects/tests/datalog/util.rkt b/collects/tests/datalog/util.rkt
new file mode 100644
index 0000000000..581c80c182
--- /dev/null
+++ b/collects/tests/datalog/util.rkt
@@ -0,0 +1,12 @@
+#lang racket
+(require rackunit
+         datalog/ast)
+
+(provide test-literal test-clause)
+
+(define (test-literal str l1 l2)
+  (test-case 
+   str (check literal-equal? l1 l2)))
+(define (test-clause str c1 c2)
+  (test-case 
+   str (check clause-equal? c1 c2)))