<s>[INST] ### Checks if the input string is a palindrome

## Step 1: Define the Problem
The problem requires a function that takes a string as input and returns True if the string is a palindrome, and False otherwise. A palindrome is a word, phrase, number, or other sequence of characters that reads the same forward and backward (ignoring spaces, punctuation, and capitalization).

## Step 2: Plan the Solution Strategy
To solve this problem, we will create a function that first cleans the input string by removing spaces and punctuation, and converting it to lower case. Then, it will compare the cleaned string with its reverse. If they are the same, the function will return True; otherwise, it will return False.

## Step 3: Implement the Solution in Python
We can implement this solution using Python. We will use the `re` module to remove spaces and punctuation, and slicing to reverse the string.

```python
import re

def is_palindrome(s):
    # Remove spaces and punctuation, and convert to lower case
    cleaned_s = re.sub(r'\W+', '', s).lower()
    
    # Compare the cleaned string with its reverse
    return cleaned_s == cleaned_s[::-1]
```

## Step 4: Test the Function
We can test the function with some examples to ensure it works correctly.

```python
print(is_palindrome("A man, a plan, a canal: Panama"))  # True
print(is_palindrome("Not a palindrome"))  # False
print(is_palindrome("Was it a car or a cat I saw?[/INST]