a # 1 60 R ' z#a on b;Lio                                               '
a # a,[1]  ' cformat                                                    '
a # a,[1]  ' z#(-1YRa#matrix a)S-1YRb#matrix b                          '
a # a,[1]  ' z#(((1YRa),z)Ya),[Lio#0]((1YRb),z)Yb                       '
a # a,[1]  ' z#C'aabz'[(2X0^=R,b)+0^=R,a]                               '
a # a,[1]  '"in case operand was empty                                  '
a # a,[1]  ' $0                                                         '
a # a,[1]  '"on - conform and catenate any structures                   '
a # a,[1]  '"from ''the apl handbook of techniques'' copyright 1978, ibm. '
a # a,[1]  '"-names or numbers may be added to lists on any shape or    '
a # a,[1]  '" character, at either end.  the output is a matrix.        '
a # a,[1]  '"-numeric matrices will be padded with zeros if they        '
a # a,[1]  '" remain numeric.                                           '
a # a,[1]  '"-character matrices will be padded with blanks.            '
a # a,[1]  '"-any operand may have any structure.                       '
a # a,[1]  '"-use Gcenteron if left-justification is not desired.       '
a # a,[1]  '"-uses: Gcformat Gmatrix                                    '
Lfx a