
    Write a function that validates whether a transit component identifier follows the maintenance logging standard, which requires all parts and systems to be labeled using only lowercase letters connected by underscores. The function should return true if the component identifier meets this standard (like "engine_cooling_system") and false if it contains any other format or characters.
    

    
import re

def text_lowercase_underscore(text):
    """
    Write a function that validates whether a transit component identifier follows the maintenance logging standard, which requires all parts and systems to be labeled using only lowercase letters connected by underscores. The function should return true if the component identifier meets this standard (like "engine_cooling_system") and false if it contains any other format or characters.
    

    """
import re

def text_lowercase_underscore(text):
    """
    Write a function that validates whether a transit component identifier follows the maintenance logging standard, which requires all parts and systems to be labeled using only lowercase letters connected by underscores. The function should return true if the component identifier meets this standard (like "engine_cooling_system") and false if it contains any other format or characters.
    

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