a # 1 60 R 'vertab                                                      '
a # a,[1]  '"vertab - calls vert function for localized a and b.        '
a # a,[1]  '"from ''the apl handbook of techniques'' copyright 1978, ibm. '
a # a,[1]  'a # vert a H b # vert b                                     '
Lfx a