Adding a minor change to allow for equality in metric goal conditions.

pddl/parser/problem.lark

@@ -20,7 +20,6 @@ basic_function_term:   NAME
                    |   LPAR NAME NAME* RPAR
 
 atomic_formula_name:   LPAR predicate NAME* RPAR
-                   |   LPAR EQUAL_OP NAME NAME RPAR
 
 goal:  LPAR GOAL gd_name RPAR
 

tests/test_parser/test_problem.py

@@ -153,3 +153,28 @@ def test_numeric_function_comparison_in_goal() -> None:
     """
     )
     ProblemParser()(problem_str)
+
+
+def test_numeric_function_equality_in_goal() -> None:
+    """Try to parse a goal with a numeric condition and function."""
+    problem_str = dedent(
+        """
+    (define (problem hello-3-times)
+        (:domain hello-world-functions)
+
+        (:init
+            ; if this was undefined, some planners would not assumed `0`
+            (= (hello_counter jimmy) 0)
+            (= (hello_counter jammy) 0)
+        )
+
+        (:goal
+            (and
+                (= 3 (hello_counter jimmy))
+                (= (hello_counter jammy) 5)
+            )
+        )
+    )
+    """
+    )
+    ProblemParser()(problem_str)