2 files changed, 24 insertions, 0 deletions
diff --git a/prolog/problems/license_plates/firstminus_2/common.py b/prolog/problems/license_plates/firstminus_2/common.py
new file mode 100644
index 0000000..9e971f6
--- /dev/null
+++ b/prolog/problems/license_plates/firstminus_2/common.py
@@ -0,0 +1,11 @@
+id = 147
+group = 'license_plates'
+number = 54
+visible = True
+facts = None
+
+solution = '''\
+firstMinus(L, L).
+firstMinus([X|T], [Y|T]) :-
+  Y is -X.
+'''
diff --git a/prolog/problems/license_plates/firstminus_2/en.py b/prolog/problems/license_plates/firstminus_2/en.py
new file mode 100644
index 0000000..9fb8c69
--- /dev/null
+++ b/prolog/problems/license_plates/firstminus_2/en.py
@@ -0,0 +1,13 @@
+id = 147
+name = 'firstMinus/2'
+slug = 'negate the first element in a list of numbers'
+
+description = '''\
+<p><code>firstMinus(L1, L2)</code>: the list <code>L2</code> is the same as <code>L1</code>, except for the first element that may be negated. Your code should return both solutions.</p>
+<pre>
+  ?- firstMinus([1,2,3], L).
+    L = [1,2,3] ;
+    L = [-1,2,3].
+</pre>'''
+
+hint = {}