2 files changed, 25 insertions, 4 deletions
diff --git a/prolog/problems/denotational_semantics/prog_8puzzle_2/common.py b/prolog/problems/denotational_semantics/prog_8puzzle_2/common.py
index 71875d4..c5b69da 100644
--- a/prolog/problems/denotational_semantics/prog_8puzzle_2/common.py
+++ b/prolog/problems/denotational_semantics/prog_8puzzle_2/common.py
@@ -1,6 +1,6 @@
 id = 172
-number = 81
-visible = False
+number = 30
+visible = True
 facts = None
 
 solution = '''\
@@ -14,3 +14,15 @@ instr172 --> [right].
 instr172 --> [up].
 instr172 --> [down].
 '''
+
+initial = '''\
+prog_8puzzle --> [begin], instructs, [end].
+
+instructs --> instr.
+instructs --> instr, instructs.
+
+instr --> [left].
+instr --> [right].
+instr --> [up].
+instr --> [down].
+'''
diff --git a/prolog/problems/denotational_semantics/prog_8puzzle_2/en.py b/prolog/problems/denotational_semantics/prog_8puzzle_2/en.py
index 7969ba4..a91e22e 100644
--- a/prolog/problems/denotational_semantics/prog_8puzzle_2/en.py
+++ b/prolog/problems/denotational_semantics/prog_8puzzle_2/en.py
@@ -2,8 +2,17 @@ name = 'prog_8puzzle/2'
 slug = '8-puzzle-solving language'
 
 description = '''\
-<p>Write a DCG for solving 8-puzzles. The first symbol in every word is <code>[begin]</code>, followed by any sequence of "instruction" symbols from the set {<code>left</code>, <code>right</code>, <code>up</code>, <code>down</code>}, and finally <code>[end]</code>. The starting symbol should be named <code>prog_8puzzle</code>.</p>
+<p>
+Write a DCG for solving 8-puzzles. The first symbol in every word is
+<code>[begin]</code>, followed by any sequence of "instruction" symbols from
+the set {<code>left</code>, <code>right</code>, <code>up</code>,
+<code>down</code>}, and finally <code>[end]</code>. The starting symbol should
+be named <code>prog_8puzzle</code>.
+</p>
 
-<p>Example words: <code>[begin,left,down,right,end]</code>, <code>[begin,down,end]</code>.</p>'''
+<p>
+Example words: <code>[begin,left,down,right,end]</code>, <code>[begin,down,end]</code>.
+</p>
+'''
 
 hint = {}