how can i represent the cutoff variable and the failure variable in this code 
function RECURSIVE-DLS(node, problem, limit) returns a solution, or failure/cutoff
if problem.GOAL-TEST(node.STATE) then return SOLUTION(node)
else if limit = 0 then return cutoff
else
cutoff occurred?←false
for each action in problem.ACTIONS(node.STATE) do
child ← CHILD-NODE(problem, node, action)
result ← RECURSIVE-DLS(child, problem, limit − 1)
if result = cutoff then cutoff occurred?← true
else if result 6= failure then return result
if cutoff occurred? then return cutoff else return failure
In the context of the `RECURSIVE-DLS` function you've provided, the concepts of "cutoff" and "failure" can be represented as distinct return values. This is often done using specific constants or enumerations that can be used to differentiate between these states. Here's how you can represent these variables in the code:

### Representation of Cutoff and Failure

1. **Cutoff**: This represents the situation where the search has reached the depth limit but has not found a solution. You can represent it with a constant value, such as `CUTOFF`.

2. **Failure**: This represents the situation where the search has explored all possibilities and has determined that no solution exists. This can also be represented with a constant, such as `FAILURE`.

### Example Code with Representations

Here's how you might define and use these variables in your code:

```python
# Constants to represent cutoff and failure
CUTOFF = "cutoff"
FAILURE = "failure"

def RECURSIVE_DLS(node, problem, limit):
    # Check if the current node is a goal state
    if problem.GOAL_TEST(node.STATE):
        return SOLUTION(node)
    # Check if we have reached the depth limit
    elif limit == 0:
        return CUTOFF
    else:
        cutoff_occurred = False
        for action in problem.ACTIONS(node.STATE):
            child = CHILD_NODE(problem, node, action)
           
 In the given code, the cutoff variable can be represented as a boolean variable `cutoff_occurred` which is set to `true` when a cutoff occurs in the recursive search. The failure variable can be represented as a special value or object that indicates failure, which is returned when the search has failed to find a solution.

Here's an example of how you could modify the code to include these variables:

```python
function RECURSIVE-DLS(node, problem, limit) returns a solution, or failure/cutoff
    if problem.GOAL-TEST(node.STATE) then return SOLUTION(node)
    else if limit = 0 then return cutoff_value
    else
        cutoff_occurred = false
        for each action in problem.ACTIONS(node.STATE) do
            child = CHILD-NODE(problem, node, action)
            result = RECURSIVE-DLS(child, problem, limit − 1)
            if result = cutoff_value then
                cutoff_occurred = true
            else if result ≠ failure then return result
        if cutoff_occurred then return cutoff_value else return failure
```

In this modified code, `cutoff_value` is a special value or object that represents a cutoff