<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def loop_template_list(loop_positions, instance, instance_type, default_template, registry):
 """ Build a list of templates from a position within a loop and a registry of templates. """

    templates = []
    local_loop_position = loop_positions[1]
    global_loop_position = loop_positions[0]
    instance_string = slugify(str(instance))

    for key in ['%s-%s' % (instance_type, instance_string),
                instance_string,
                instance_type,
                'default']:
        try:
            templates.append(registry[key][global_loop_position])
        except KeyError:
            pass

    templates.append(
        append_position(default_template, global_loop_position, '-'))
    templates.append(
        append_position(default_template, local_loop_position, '_'))
    templates.append(default_template)

    return templates