a # 1 60 R ' l#firstv m                                                 '
a # a,[1]  ' l#(vIv)=IRv                                                '
a # a,[1]  ' $0                                                         '
a # a,[1]  '"firstv - select first or only appearance in vector         '
a # a,[1]  '"from ''the apl handbook of techniques'' copyright 1978, ibm. '
a # a,[1]  '" see Gfirstm                                               '
Lfx a