diff --git a/test17.ss b/test17.ss
new file mode 100644
index 0000000..0ddaf4b
--- /dev/null
+++ b/test17.ss
@@ -0,0 +1,435 @@
+#!r6rs
+
+(import (rnrs)
+	(QobiScheme)
+	(nondeterministic-scheme)
+	(nondeterministic-constraints)
+	(nondeterministic-lifting)
+	(wwd))
+
+(define (write-grids x y z sentences)
+ (set-nondeterministic-strategy! 'ac)
+ (initialize-domain-variables!)
+ (system "rm solution-*.logs")
+ (domain
+  (let ((i 0) (grid (create-grid x y z)))
+   (assert-lincoln-log-grammar-constraints! grid)
+   (for-each (lambda (sentence) (assert! (a-meaning-constraint sentence grid)))
+	     sentences)
+   (nondeterministic-solution (domain-variables))
+   (write-grid grid (string-append "solution-" (number->string i) ".logs"))
+   (set! i (+ i 1))
+   (fail)))
+ (system "./gui"))
+
+(define (possibly-true? words grid)
+ (initialize-domain-variables!)
+ (call-with-current-continuation
+  (lambda (return)
+   (domain (let ((grid (lift-grid grid)))
+	    (assert-lincoln-log-grammar-constraints! grid)
+	    (assert! (a-meaning-constraint words grid))
+	    (nondeterministic-solution (domain-variables))
+	    (return #t)))
+   #f)))
+
+(define (all-grids x y z sentences)
+ (domain (let ((grid (create-grid x y z)))
+	  (assert-lincoln-log-grammar-constraints! grid)
+	  (for-each
+	   (lambda (sentence) (assert! (a-meaning-constraint sentence grid)))
+	   sentences)
+	  (nondeterministic-solution (domain-variables))
+	  (grid-binding grid))))
+
+(define (first-grid x y z sentences)
+ (set-nondeterministic-strategy! 'ac)
+ (initialize-domain-variables!)
+ (call-with-current-continuation
+  (lambda (return)
+   (domain (let ((grid (create-grid x y z)))
+	    (assert-lincoln-log-grammar-constraints! grid)
+	    (for-each
+	     (lambda (sentence) (assert! (a-meaning-constraint sentence grid)))
+	     sentences)
+	    (nondeterministic-solution (domain-variables))
+	    (return (grid-binding grid))))
+   #f)))
+
+(define (all-grids-capped n x y z sentences)
+ (initialize-domain-variables!)
+ (call-with-current-continuation
+  (lambda (return)
+   (domain (let ((grid (create-grid x y z)) (grids '()))
+	    (assert-lincoln-log-grammar-constraints! grid)
+	    (for-each
+	     (lambda (sentence) (assert! (a-meaning-constraint sentence grid)))
+	     sentences)
+	    (nondeterministic-solution (domain-variables))
+	    (when (= (length grids) n) (return (reverse grids)))
+	    (set! grids (cons (grid-binding grid) grids))
+	    (grid-binding grid))))))
+
+(define (all-true-sentences-of-length n grid)
+ (remove-if-not (lambda (words) (possibly-true? words grid))
+		(all-sentences n)))
+
+(define (description n grid)
+ (set-nondeterministic-strategy! 'ac)
+ (initialize-domain-variables!)
+ (call-with-current-continuation
+  (lambda (return)
+   (let loop ((candidates (all-true-sentences-of-length n grid))
+	      (sentences '()))
+    (let ((alternative
+	   (map-reduce
+	    (lambda (alternative1 alternative2)
+	     (write (list alternative1 alternative2)) (newline) ;debugging
+	     (when (= (second alternative2) 1) (return (first alternative2)))
+	     (if (<= (second alternative1) (second alternative2))
+		 alternative1
+		 alternative2))
+	    (list #f
+		  (length (all-grids-capped 100
+					    (max-x grid)
+					    (max-y grid)
+					    (max-z grid)
+					    sentences)))
+	    (lambda (candidate)
+	     (write candidate) (newline) ;debugging
+	     (list candidate
+		   (length (all-grids-capped 100
+					     (max-x grid)
+					     (max-y grid)
+					     (max-z grid)
+					     (cons candidate sentences)))))
+	    candidates)))
+     (if (eq? (first alternative) #f)
+	 sentences
+	 (loop (removeq (first alternative) candidates)
+	       (cons (first alternative) sentences))))))))
+
+(define (description2 n grid)
+ (set-nondeterministic-strategy! 'ac)
+ (initialize-domain-variables!)
+ (let loop ((candidates
+	     (map-reduce-n
+	      append
+	      '()
+	      (lambda (i) (all-true-sentences-of-length (+ i 1) grid))
+	      n))
+	    (keep '()))
+  (cond ((null? candidates) keep)
+	;; needs work: hardwired to 2; should be to duplicity in full set
+	((= (length (all-grids-capped 2
+				      (max-x grid) (max-y grid) (max-z grid)
+				      (append (rest candidates) keep)))
+	    2)
+	 (write (list 'keep (first candidates))) (newline) ;debugging
+	 (loop (rest candidates) (cons (first candidates) keep)))
+	(else
+	 (write (list 'drop (first candidates))) (newline) ;debugging
+	 (loop (rest candidates) keep)))))
+
+(define (test1)
+ (set-nondeterministic-strategy! 'ac)
+ (initialize-domain-variables!)
+ (system "rm solution-*.logs")
+ (domain
+  (let ((i 0) (grid (create-grid 2 1 2)))
+   (assert-lincoln-log-grammar-constraints! grid)
+   (nondeterministic-solution (domain-variables))
+   (write-grid grid (string-append "solution-" (number->string i) ".logs"))
+   (set! i (+ i 1))
+   (fail)))
+ (system "./gui"))
+
+(define (test2)
+ (set-nondeterministic-strategy! 'ac)
+ (initialize-domain-variables!)
+ (system "rm solution-*.logs")
+ (domain
+  (let ((i 0) (grid (create-grid 1 4 1)))
+   (assert-lincoln-log-grammar-constraints! grid)
+   (nondeterministic-solution (domain-variables))
+   (write-grid grid (string-append "solution-" (number->string i) ".logs"))
+   (set! i (+ i 1))
+   (fail)))
+ (system "./gui"))
+
+(define (test3)
+ (set-nondeterministic-strategy! 'ac)
+ (initialize-domain-variables!)
+ (system "rm solution-*.logs")
+ (domain
+  (let ((i 0) (grid (create-grid 2 8 1)))
+   (assert-lincoln-log-grammar-constraints! grid)
+   (assert! (some-constraint
+	     (lambda (thing) (wall?-constraint grid thing)) (things grid)))
+   (nondeterministic-solution (domain-variables))
+   (write-grid grid (string-append "solution-" (number->string i) ".logs"))
+   (set! i (+ i 1))
+   (fail)))
+ (system "./gui"))
+
+(define (test4)
+ (set-nondeterministic-strategy! 'ac)
+ (initialize-domain-variables!)
+ (system "rm solution-*.logs")
+ (domain
+  (let ((i 0) (grid (create-grid 2 8 1)))
+   (assert-lincoln-log-grammar-constraints! grid)
+   (assert! (some-constraint
+	     (lambda (thing) (window?-constraint grid thing)) (things grid)))
+   (nondeterministic-solution (domain-variables))
+   (write-grid grid (string-append "solution-" (number->string i) ".logs"))
+   (set! i (+ i 1))
+   (fail)))
+ (system "./gui"))
+
+(define (test5)
+ (set-nondeterministic-strategy! 'ac)
+ (initialize-domain-variables!)
+ (system "rm solution-*.logs")
+ (domain
+  (let ((i 0) (grid (create-grid 2 8 1)))
+   (assert-lincoln-log-grammar-constraints! grid)
+   (assert! (some-constraint
+	     (lambda (thing) (door?-constraint grid thing)) (things grid)))
+   (nondeterministic-solution (domain-variables))
+   (write-grid grid (string-append "solution-" (number->string i) ".logs"))
+   (set! i (+ i 1))
+   (fail)))
+ (system "./gui"))
+
+;;; works, 2 solutions probably 2x lexical
+(define (test6) (write-grids 2 5 1 '((some wall has some window))))
+
+(define (test7)
+ (set-nondeterministic-strategy! 'ac)
+ (initialize-domain-variables!)
+ (system "rm solution-*.logs")
+ (domain
+  (let ((i 0) (grid (create-grid 2 6 1)))
+   (assert-lincoln-log-grammar-constraints! grid)
+   (assert! (some-constraint
+	     (lambda (thing1)
+	      (and-constraint
+	       (wall?-constraint grid thing1)
+	       (some-constraint
+		(lambda (thing2)
+		 (and-constraint (window?-constraint grid thing2)
+				 (if (thing-inside? thing2 thing1)
+				     (true-domain-variable)
+				     (false-domain-variable))))
+		(things grid))))
+	     (things grid)))
+   (nondeterministic-solution (domain-variables))
+   (write-grid grid (string-append "solution-" (number->string i) ".logs"))
+   (set! i (+ i 1))
+   (fail)))
+ (system "./gui"))
+
+(define (test8)
+ (set-nondeterministic-strategy! 'ac)
+ (initialize-domain-variables!)
+ (system "rm solution-*.logs")
+ (domain
+  (let ((i 0) (grid (create-grid 2 6 1)))
+   (assert-lincoln-log-grammar-constraints! grid)
+   (assert!
+    (evaluate
+     (parse-expression
+      '(some
+	(lambda (thing1)
+	 (and (wall? thing1)
+	      (some (lambda (thing2)
+		     (and (window? thing2) (inside? thing2 thing1)))))))
+      (parse-type *s*))
+     '()
+     grid))
+   (nondeterministic-solution (domain-variables))
+   (write-grid grid (string-append "solution-" (number->string i) ".logs"))
+   (set! i (+ i 1))
+   (fail)))
+ (system "./gui"))
+
+(define (test9)
+ (set-nondeterministic-strategy! 'ac)
+ (initialize-domain-variables!)
+ (system "rm solution-*.logs")
+ (domain
+  (let ((i 0) (grid (create-grid 2 6 1)))
+   (assert-lincoln-log-grammar-constraints! grid)
+   (assert! (and-constraint
+	     (some-constraint
+	      (lambda (thing) (wall?-constraint grid thing))
+	      (things grid))
+	     (not-constraint
+	      (some-constraint
+	       (lambda (thing) (window?-constraint grid thing))
+	       (things grid)))
+	     (not-constraint
+	      (some-constraint
+	       (lambda (thing) (door?-constraint grid thing))
+	       (things grid)))))
+   (nondeterministic-solution (domain-variables))
+   (write-grid grid (string-append "solution-" (number->string i) ".logs"))
+   (set! i (+ i 1))
+   (fail)))
+ (system "./gui"))
+
+;;; works, 1 solution
+(define (test10) (write-grids 2 7 1 '((some window exists) (some door exists))))
+
+;;; works, 1 solution
+(define (test11) (write-grids 2 9 1 '((two window exists))))
+
+(define (test12 n)
+ (set-nondeterministic-strategy! 'ac)
+ (all-sentences n))
+
+(define (test13)
+ (set-nondeterministic-strategy! 'ac)
+ (initialize-domain-variables!)
+ (all-true-sentences-of-length
+  3 (first-grid 2 8 1 '((some window exists) (some door exists)))))
+
+(define (test13a)
+ (description 3 (first-grid 2 8 1 '((some window exists) (some door exists)))))
+
+(define (test14)
+ (set-nondeterministic-strategy! 'ac)
+ (initialize-domain-variables!)
+ (all-true-sentences-of-length 3 (first-grid 2 10 1 '((two window exists)))))
+
+(define (test14a) (description 3 (first-grid 2 10 1 '((two window exists)))))
+
+(define (test15)
+ ;; 224 solutions, lots of non-things
+ (write-grids
+  2 5 3 '((four wall exists) (two window exists) (four door exists))))
+
+;;; works, 1 solution
+(define (test16) (write-grids 2 4 3 '((seven door exists))))
+
+;;; works, 1 solution
+(define (test17) (write-grids 2 5 1 '((some solid three-high wall exists))))
+
+(define (test18)
+ (write-grids
+  2 6 3 '((every wall is solid) (every wall is three-high) (five wall exists))))
+
+(define (test18a)
+ (write-grids 2 6 3 '((every wall is three-high) (five solid wall exists))))
+
+(define (test18b)
+ (write-grids 2 6 3 '((every wall is solid) (five three-high wall exists))))
+
+(define (test18c) (write-grids 2 6 3 '((five solid three-high wall exists))))
+
+(define (test19)
+ ;; 25 solutions, some disconnected, lots of non-things
+ (write-grids 2 5 3 '((two solid wall exists) (three window exists))))
+
+(define (test20)
+ (set-nondeterministic-strategy! 'ac)
+ (initialize-domain-variables!)
+ (system "rm solution-*.logs")
+ (domain
+  (let ((i 0) (grid (create-grid 2 5 3)))
+   (assert-lincoln-log-grammar-constraints! grid)
+   (assert! (every-constraint
+	     (lambda (thing1)
+	      (or-constraint
+	       (not-constraint (wall?-constraint grid thing1))
+	       (some-constraint
+		(lambda (thing2)
+		 (and-constraint
+		  (or-constraint (window?-constraint grid thing2)
+				 (wall?-constraint grid thing2))
+		  (if (thing-inside? thing2 thing1)
+		      (true-domain-variable)
+		      (false-domain-variable))))
+		(things grid))
+	       (solid?-constraint grid thing1)))
+	     (things grid)))
+   (nondeterministic-solution (domain-variables))
+   (write-grid grid (string-append "solution-" (number->string i) ".logs"))
+   (set! i (+ i 1))
+   (fail)))
+ (system "./gui"))
+
+(define (test21)
+ (set-nondeterministic-strategy! 'ac)
+ (initialize-domain-variables!)
+ (system "rm solution-*.logs")
+ (domain
+  (let ((i 0) (grid (create-grid 2 5 3)))
+   (assert-lincoln-log-grammar-constraints! grid)
+   (assert! (every-constraint
+	     (lambda (thing1)
+	      (or-constraint
+	       (not-constraint (wall?-constraint grid thing1))
+	       (solid?-constraint grid thing1)))
+	     (things grid)))
+   (nondeterministic-solution (domain-variables))
+   (write-grid grid (string-append "solution-" (number->string i) ".logs"))
+   (set! i (+ i 1))
+   (fail)))
+ (system "./gui"))
+
+(define (test22)
+ ;; works, 1 solution
+ (write-grids 2 6 3 '((two solid two-wide three-high wall exists)
+		      (three solid one-wide three-high wall exists))))
+
+(define (test23)
+ (write-grids 2 6 3 '((five wall exists)
+		      (every wall is three-high)
+		      (two wall is two-wide)
+		      (three wall is one-wide)
+		      (one window exists)
+		      (two door exists)
+		      (every door is two-high)
+		      (three wall is solid))))
+
+(define (test24)
+ ;; works, 12 solutions
+ ;; 3x for wall containing door, 2x mirror, probably 2x lexical
+ (write-grids 2 6 3 '((three one-wide wall exists)
+		      (two two-wide wall exists)
+		      (two solid one-wide wall exists)
+		      (one solid two-wide wall exists)
+		      (every wall is three-high)
+		      (two two-high door exists)
+		      (some window is-to-the-left-of some door))))
+
+(define (test25)
+ (write-grids 2 6 3 '((two one-wide wall exists)
+		      (two two-wide wall exists)
+		      (two solid one-wide wall exists)
+		      (one solid two-wide wall exists)
+		      (every wall is three-high)
+		      (some window is-to-the-left-of some two-high door))))
+
+;;; works, 1 solution
+(define (test26) (write-grids 2 6 3 '((seven two-high door exists))))
+
+(define (test26a)
+ (description 4 (first-grid 2 6 3 '((seven two-high door exists)))))
+
+;;; works, 35 solutions
+(define (test27)
+ (write-grids 2 6 3 '((four two-high door exists) (three window exists))))
+
+(define (test28)
+ (description
+  4 (first-grid 2 6 3 '((every wall is three-high) (five solid wall exists)))))
+
+(define (test29)
+ (description2
+  4 (first-grid 2 4 3 '((two solid two-wide two-high wall exists)
+			(three solid one-wide two-high wall exists)))))
+
+;;(test29)