@pimms.param<EOL><INDENT>def images(imgs):<DEDENT>
if   imgs is None:        return pyr.m()<EOL>elif pimms.is_pmap(imgs): return imgs<EOL>elif pimms.is_map(imgs):  return pyr.pmap(imgs)<EOL>else: raise ValueError('<STR_LIT>')<EOL>
sub.images is a persistent map of MRImages tracked by the given subject sub.