mk: phase 7 — table-1 + table-3, Ackermann canary

Two more arities of the naive memoization wrapper:

table-1: predicate (1-arg) tabling. Cache entry is :ok / :no.
  Demonstrated with a tabled membero-as-predicate.

table-3: 3-arg (i1 i2 output) tabling. Cache key joins the two
  inputs; cache value is the output value list.
  Canonical demo: tabled Ackermann.

  (ack-o 0 0 q) -> 1
  (ack-o 2 3 q) -> 9
  (ack-o 3 3 q) -> 61

A(3,3) executes A(2,..) many times, A(1,..) more, A(0,..) most. With
table-3 each (m, n) pair is computed once.

6 new tests, 644/644 cumulative.

lib/minikanren/tests/tabling-more.sx

@@ -0,0 +1,55 @@
+;; lib/minikanren/tests/tabling-more.sx — table-1 + table-3.
+
+;; --- table-1 (predicate caching) ---
+
+(define
+  tab-in-list
+  (table-1
+    "in-list"
+    (fn
+      (x)
+      (membero
+        x
+        (list 1 2 3 4 5)))))
+
+(mk-tab-clear!)
+(mk-test
+  "table-1-hit"
+  (run* q (tab-in-list 3))
+  (list (make-symbol "_.0")))
+(mk-test "table-1-miss-no" (run* q (tab-in-list 99)) (list))
+(mk-test
+  "table-1-replay"
+  (run* q (tab-in-list 3))
+  (list (make-symbol "_.0")))
+
+;; --- table-3 (Ackermann) ---
+
+(define
+  ack-o
+  (table-3
+    "ack"
+    (fn
+      (m n result)
+      (conde
+        ((== m 0) (pluso-i n 1 result))
+        ((fresh (m-1) (lto-i 0 m) (== n 0) (minuso-i m 1 m-1) (ack-o m-1 1 result)))
+        ((fresh (m-1 n-1 inner) (lto-i 0 m) (lto-i 0 n) (minuso-i m 1 m-1) (minuso-i n 1 n-1) (ack-o m n-1 inner) (ack-o m-1 inner result)))))))
+
+(mk-tab-clear!)
+(mk-test
+  "ack-0-0"
+  (run* q (ack-o 0 0 q))
+  (list 1))
+(mk-tab-clear!)
+(mk-test
+  "ack-2-3"
+  (run* q (ack-o 2 3 q))
+  (list 9))
+(mk-tab-clear!)
+(mk-test
+  "ack-3-3"
+  (run* q (ack-o 3 3 q))
+  (list 61))
+
+(mk-tests-run!)