def parse_typedefs_file(typedefsFile):
    """
    Parses the typedefs file containing the typedefs defined in the input 
    ontology file. These typedefs will be considered the valid relationships 
    that terms may use.
    """
    typedefs = []

    typedefsFh = open(typedefsFile)
    for typedef in typedefsFh:
        typedefs.append(typedef.strip())

    typedefsFh.close()
    return typedefs