a # 1 60 R ' r#w xvec b                                                 '
a # a,[1]  ' r#(I-1Yr+~Lio)Er#(IRb)++\wXb#~b                            '
a # a,[1]  ' $0                                                         '
a # a,[1]  '"xvec - expand logical vector                               '
a # a,[1]  '"from ''the apl handbook of techniques'' copyright 1978, ibm. '
a # a,[1]  '"-a binary indication of a compressed data structure will be'
a # a,[1]  '" transformed into an expansion vector that can inject w    '
a # a,[1]  '" spaces (or w zeros in a numeric structure) ahead of the   '
a # a,[1]  '" field or group to be shifted.                             '
a # a,[1]  '"-since the expansion can be made along any axis, the length'
a # a,[1]  '" of the binary vector, b, must equal the length of the axis'
a # a,[1]  '"-b is a logical vector, with zeros indicating the beginning'
a # a,[1]  '" of each field, before which wR0 will be inserted.         '
a # a,[1]  '" the original zeros will be converted to ones.             '
Lfx a