a # 1 60 R ' t#logical a                                                '
a # a,[1]  ' t#&/(,a)E1 0                                               '
a # a,[1]  ' $0                                                         '
a # a,[1]  '"logical - returns 1 if structure contains only 1 and 0.    '
a # a,[1]  '"from ''the apl handbook of techniques'' copyright 1978, ibm. '
Lfx a