
    Write a function that validates whether a transaction identifier follows the bank's secure naming convention by checking if it consists only of lowercase letters joined with underscores. The function should return true if the transaction ID matches this secure format and false for any deviation, helping prevent fraudulent transactions that might use irregular identifier patterns.
    

    
import re

def text_lowercase_underscore(text):
    """
    Write a function that validates whether a transaction identifier follows the bank's secure naming convention by checking if it consists only of lowercase letters joined with underscores. The function should return true if the transaction ID matches this secure format and false for any deviation, helping prevent fraudulent transactions that might use irregular identifier patterns.
    

    """
import re

def text_lowercase_underscore(text):
    """
    Write a function that validates whether a transaction identifier follows the bank's secure naming convention by checking if it consists only of lowercase letters joined with underscores. The function should return true if the transaction ID matches this secure format and false for any deviation, helping prevent fraudulent transactions that might use irregular identifier patterns.
    

    """
    patterns = '^[a-z]+_[a-z]+$'
    if re.search(patterns, text):
        return True
    else:
        return False