a # 1 60 R ' z#b by c                                                   '
a # a,[1]  ' ''zero is invalid argument''hang 0=1Yc                       '
a # a,[1]  ' z#(1,Rz)Rz#b,c                                             '
a # a,[1]  ' $0                                                         '
a # a,[1]  '"by - see Gto.                                              '
a # a,[1]  '"from ''the apl handbook of techniques'' copyright 1978, ibm. '
Lfx a