Checkpoint

tests/parser/grammars/LogicGrammarTests.kt

@@ -129,4 +129,16 @@ class LogicGrammarTests {
         val conjunction = rule.body as CompoundTerm
         assertEquals("invited/2", (conjunction.arguments[0] as CompoundTerm).functor, "Expected functor 'invited/2'")
     }
+
+    @Test
+    fun `parse constraints`() {
+        val input = ":- a."
+
+        val result = parser.parseToEnd(input)
+
+        assertEquals(1, result.size, "Expected 1 rule")
+        assertTrue(result[0] is Rule, "Expected a rule")
+        val rule = result[0] as Rule
+        assertEquals("/_", rule.head.functor, "Expected a constraint")
+    }
 }