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diff --git a/prolog/problems/denotational_semantics/algol_3/en.py b/prolog/problems/denotational_semantics/algol_3/en.py
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+++ b/prolog/problems/denotational_semantics/algol_3/en.py
@@ -0,0 +1,33 @@
+id = 176
+name = 'algol/3'
+slug = 'interpreter for mini-algol'
+
+description = '''\
+<p>A DCG for mini-algol.</p>
+<pre>
+  % apply a function to a starting state
+  ?- apply([a=2], Out, fun(_In, Out, eval(a+3, _In, Out))).
+    Out = 5.
+
+  % a := a+b
+  % b := a-b
+  % a := a-b
+  ?- _Program = [begin,a,:=,a+b,b,:=,a-b,a,:=,a-b,end],
+      algol(_F, _Program, []),
+      apply([a=3,b=5], Output, _F).
+    Output = [a=5,b=3,printout=[]].
+
+  % a := 0
+  % while a < 10 do
+  % begin
+  %   print(a)
+  %   a := a+1
+  % end
+  ?- _Program = [begin,a,:=,0,while,a,<,10,do,begin,print(a),a,:=,a+1,end,end],
+      algol(_F, _Program, []),
+      apply([a=3], Output, _F).
+    Output = [a=10,printout=[0,1,2,3,4,5,6,7,8,9]].
+</pre>
+'''
+
+hint = {}