(test-group "symbolo tests"

  (test "symbolo-1"
        (run* (q) (symbolo q))
        '((_.0 (sym _.0))))

  (test "symbolo-2"
        (run* (q) (symbolo q) (== 'x q))
        '(x))

  (test "symbolo-3"
        (run* (q) (== 'x q) (symbolo q))
        '(x))

  (test "symbolo-4"
        (run* (q) (== 5 q) (symbolo q))
        '())

  (test "symbolo-5"
        (run* (q) (symbolo q) (== 5 q))
        '())

  (test "symbolo-6"
        (run* (q) (symbolo q) (== `(1 . 2) q))
        '())

  (test "symbolo-7"
        (run* (q) (== `(1 . 2) q) (symbolo q))
        '())

  (test "symbolo-8"
        (run* (q) (fresh (x) (symbolo x)))
        '(_.0))

  (test "symbolo-9"
        (run* (q) (fresh (x) (symbolo x)))
        '(_.0))

  (test "symbolo-10"
        (run* (q) (fresh (x) (symbolo x) (== x q)))
        '((_.0 (sym _.0))))

  (test "symbolo-11"
        (run* (q) (fresh (x) (symbolo q) (== x q) (symbolo x)))
        '((_.0 (sym _.0))))

  (test "symbolo-12"
        (run* (q) (fresh (x) (symbolo q) (symbolo x) (== x q)))
        '((_.0 (sym _.0))))

  (test "symbolo-13"
        (run* (q) (fresh (x) (== x q) (symbolo q) (symbolo x)))
        '((_.0 (sym _.0))))

  (test "symbolo-14-a"
        (run* (q) (fresh (x) (symbolo q) (== 'y x)))
        '((_.0 (sym _.0))))

  (test "symbolo-14-b"
        (run* (q) (fresh (x) (symbolo q) (== 'y x) (== x q)))
        '(y))

  (test "symbolo-15"
        (run* (q) (fresh (x) (== q x) (symbolo q) (== 5 x)))
        '())

  (test "symbolo-16-a"
        (run* (q) (symbolo q) (=/= 5 q))
        '((_.0 (sym _.0))))

  (test "symbolo-16-b"
        (run* (q) (=/= 5 q) (symbolo q))
        '((_.0 (sym _.0))))

  (test "symbolo-17"
        (run* (q) (symbolo q) (=/= `(1 . 2) q))
        '((_.0 (sym _.0))))

  (test "symbolo-18"
        (run* (q) (symbolo q) (=/= 'y q))
        '((_.0 (=/= ((_.0 y))) (sym _.0))))

  (test "symbolo-19"
        (run* (q)
          (fresh (x y)
            (symbolo x)
            (symbolo y)
            (== `(,x ,y) q)))
        '(((_.0 _.1) (sym _.0 _.1))))

  (test "symbolo-20"
        (run* (q)
          (fresh (x y)
            (== `(,x ,y) q)
            (symbolo x)
            (symbolo y)))
        '(((_.0 _.1) (sym _.0 _.1))))

  (test "symbolo-21"
        (run* (q)
          (fresh (x y)
            (== `(,x ,y) q)
            (symbolo x)
            (symbolo x)))
        '(((_.0 _.1) (sym _.0))))

  (test "symbolo-22"
        (run* (q)
          (fresh (x y)
            (symbolo x)
            (symbolo x)
            (== `(,x ,y) q)))
        '(((_.0 _.1) (sym _.0))))

  (test "symbolo-23"
        (run* (q)
          (fresh (x y)
            (symbolo x)
            (== `(,x ,y) q)
            (symbolo x)))
        '(((_.0 _.1) (sym _.0))))

  (test "symbolo-24-a"
        (run* (q)
          (fresh (w x y z)
            (=/= `(,w . ,x) `(,y . ,z))
            (symbolo w)
            (symbolo z)))
        '(_.0))

  (test "symbolo-24-b"
        (run* (q)
          (fresh (w x y z)
            (=/= `(,w . ,x) `(,y . ,z))
            (symbolo w)
            (symbolo z)
            (== `(,w ,x ,y ,z) q)))
        '(((_.0 _.1 _.2 _.3)
           (=/= ((_.0 _.2) (_.1 _.3)))
           (sym _.0 _.3))))

  (test "symbolo-24-c"
        (run* (q)
          (fresh (w x y z)
            (=/= `(,w . ,x) `(,y . ,z))
            (symbolo w)
            (symbolo y)
            (== `(,w ,x ,y ,z) q)))
        '(((_.0 _.1 _.2 _.3)
           (=/= ((_.0 _.2) (_.1 _.3)))
           (sym _.0 _.2))))

  (test "symbolo-24-d"
        (run* (q)
          (fresh (w x y z)
            (=/= `(,w . ,x) `(,y . ,z))
            (symbolo w)
            (symbolo y)
            (== w y)
            (== `(,w ,x ,y ,z) q)))
        '(((_.0 _.1 _.0 _.2)
           (=/= ((_.1 _.2)))
           (sym _.0))))

  (test "symbolo-25"
        (run* (q)
          (fresh (w x)
            (=/= `(,w . ,x) `(5 . 6))
            (== `(,w ,x) q)))
        '(((_.0 _.1) (=/= ((_.0 5) (_.1 6))))))

  (test "symbolo-26"
        (run* (q)
          (fresh (w x)
            (=/= `(,w . ,x) `(5 . 6))
            (symbolo w)
            (== `(,w ,x) q)))
        '(((_.0 _.1) (sym _.0))))

  (test "symbolo-27"
        (run* (q)
          (fresh (w x)
            (symbolo w)
            (=/= `(,w . ,x) `(5 . 6))
            (== `(,w ,x) q)))
        '(((_.0 _.1) (sym _.0))))

  (test "symbolo-28"
        (run* (q)
          (fresh (w x)
            (symbolo w)
            (=/= `(5 . 6) `(,w . ,x))
            (== `(,w ,x) q)))
        '(((_.0 _.1) (sym _.0))))

  (test "symbolo-29"
        (run* (q)
          (fresh (w x)
            (symbolo w)
            (=/= `(5 . ,x) `(,w . 6))
            (== `(,w ,x) q)))
        '(((_.0 _.1) (sym _.0))))

  (test "symbolo-30"
        (run* (q)
          (fresh (w x)
            (symbolo w)
            (=/= `(z . ,x) `(,w . 6))
            (== `(,w ,x) q)))
        '(((_.0 _.1) (=/= ((_.0 z) (_.1 6))) (sym _.0))))

  (test "symbolo-31-a"
        (run* (q)
          (fresh (w x y z)
            (== x 5)
            (=/= `(,w ,y) `(,x ,z))
            (== w 5)
            (== `(,w ,x ,y ,z) q)))
        '(((5 5 _.0 _.1) (=/= ((_.0 _.1))))))

  (test "symbolo-31-b"
        (run* (q)
          (fresh (w x y z)
            (=/= `(,w ,y) `(,x ,z))
            (== w 5)
            (== x 5)
            (== `(,w ,x ,y ,z) q)))
        '(((5 5 _.0 _.1) (=/= ((_.0 _.1))))))

  (test "symbolo-31-c"
        (run* (q)
          (fresh (w x y z)
            (== w 5)
            (=/= `(,w ,y) `(,x ,z))
            (== `(,w ,x ,y ,z) q)
            (== x 5)))
        '(((5 5 _.0 _.1) (=/= ((_.0 _.1))))))

  (test "symbolo-31-d"
        (run* (q)
          (fresh (w x y z)
            (== w 5)
            (== x 5)
            (=/= `(,w ,y) `(,x ,z))
            (== `(,w ,x ,y ,z) q)))
        '(((5 5 _.0 _.1) (=/= ((_.0 _.1))))))


  (test "symbolo-32-a"
        (run* (q)
          (fresh (w x y z)
            (== x 'a)
            (=/= `(,w ,y) `(,x ,z))
            (== w 'a)
            (== `(,w ,x ,y ,z) q)))
        '(((a a _.0 _.1) (=/= ((_.0 _.1))))))

  (test "symbolo-32-b"
        (run* (q)
          (fresh (w x y z)
            (=/= `(,w ,y) `(,x ,z))
            (== w 'a)
            (== x 'a)
            (== `(,w ,x ,y ,z) q)))
        '(((a a _.0 _.1) (=/= ((_.0 _.1))))))

  (test "symbolo-32-c"
        (run* (q)
          (fresh (w x y z)
            (== w 'a)
            (=/= `(,w ,y) `(,x ,z))
            (== `(,w ,x ,y ,z) q)
            (== x 'a)))
        '(((a a _.0 _.1) (=/= ((_.0 _.1))))))

  (test "symbolo-32-d"
        (run* (q)
          (fresh (w x y z)
            (== w 'a)
            (== x 'a)
            (=/= `(,w ,y) `(,x ,z))
            (== `(,w ,x ,y ,z) q)))
        '(((a a _.0 _.1) (=/= ((_.0 _.1))))))
  )