chore: fix lint from inadequate typing

mathy_core/rules/multiplicative_inverse.py

@@ -52,25 +52,25 @@ def apply_to(self, node: MathExpression) -> ExpressionChangeRule:
         assert tree_type is not None, "call can_apply_to before applying a rule"
         change.save_parent()  # connect result to node.parent
 
-        # Handle the division based on the tree type
-        if tree_type == _OP_DIVISION_EXPRESSION:
-            result = MultiplyExpression(
-                node.left.clone(),
-                DivideExpression(ConstantExpression(1), node.right.clone()),
-            )
+        assert node.left is not None, "Division must have a left child"
+        assert node.right is not None, "Division must have a right child"
 
-        elif tree_type == _OP_DIVISION_NEGATIVE_DENOMINATOR:
+        if tree_type == _OP_DIVISION_NEGATIVE_DENOMINATOR:
             # For division by a negative denominator, negate the numerator and use the positive reciprocal
+            assert isinstance(
+                node.right, NegateExpression
+            ), "Right child must be a NegateExpression"
+            child = node.right.get_child()
+            assert child is not None, "NegateExpression must have a child"
             result = MultiplyExpression(
                 node.left.clone(),
-                DivideExpression(
-                    ConstantExpression(-1), node.right.get_child().clone()
-                ),
+                DivideExpression(ConstantExpression(-1), child.clone()),
             )
-
+        # Handle the division based on the tree type
         else:
-            raise NotImplementedError(
-                "Unsupported tree configuration for MultiplicativeInverseRule"
+            result = MultiplyExpression(
+                node.left.clone(),
+                DivideExpression(ConstantExpression(1), node.right.clone()),
             )
 
         result.set_changed()  # mark this node as changed for visualization