def is_concept(uri):
    """
    >>> is_concept('/c/sv/klänning')
    True
    >>> is_concept('/x/en/ly')
    False
    >>> is_concept('/a/[/r/Synonym/,/c/ro/funcția_beta/,/c/en/beta_function/]')
    False
    """
    return uri.startswith('/c/')
