2 files changed, 27 insertions, 0 deletions
diff --git a/prolog/problems/denotational_semantics/prog_8puzzle_2/common.py b/prolog/problems/denotational_semantics/prog_8puzzle_2/common.py
new file mode 100644
index 0000000..4cc9c9e
--- /dev/null
+++ b/prolog/problems/denotational_semantics/prog_8puzzle_2/common.py
@@ -0,0 +1,17 @@
+id = 172
+group = 'denotational_semantics'
+number = 81
+visible = True
+facts = None
+
+solution = '''\
+prog_8puzzle --> [begin], instructs172, [end].
+
+instructs172 --> instr172.
+instructs172 --> instr172, instructs172.
+
+instr172 --> [left].
+instr172 --> [right].
+instr172 --> [up].
+instr172 --> [down].
+'''
diff --git a/prolog/problems/denotational_semantics/prog_8puzzle_2/en.py b/prolog/problems/denotational_semantics/prog_8puzzle_2/en.py
new file mode 100644
index 0000000..eebf07b
--- /dev/null
+++ b/prolog/problems/denotational_semantics/prog_8puzzle_2/en.py
@@ -0,0 +1,10 @@
+id = 172
+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>Example words: <code>[begin,left,down,right,end]</code>, <code>[begin,down,end]</code>.</p>'''
+
+hint = {}