a # 1 63 R ' r#n uline k;l;Lio;j;i                                         '
a # a,[1]  ' k#matrix Fk                                                   '
a # a,[1]  ' ''''''matrix has rows numbered: '''',Fj''escapex~&/nEj#Ii#(Lio#1)YRk'
a # a,[1]  ' r#(l#(1 xvec i cvec 1+n),0)`\k                                '
a # a,[1]  ' r#(_j,0)Ur fills(~l)`\(((j#i>S/n)+R,n),1URk)R(V`/k^='' '')\''-''  '
a # a,[1]  ' $0                                                            '
a # a,[1]  '"uline - underline specified rows of character matrix          '
a # a,[1]  '"from ''the apl handbook of techniques'' copyright 1978, ibm.    '
a # a,[1]  '"-returns an expanded matrix with underscores inserted,        '
a # a,[1]  '" as indicated by n, a vector or row numbers Lio#1.            '
a # a,[1]  '"-underlines will not appear in columns that are always        '
a # a,[1]  '" blank.                                                       '
a # a,[1]  '"-given a character vector, Guscore is much faster than        '
a # a,[1]  '" Guline.                                                      '
a # a,[1]  '"-uses: Gmatrix Gexpacex Gxvex Gcvec Gfills                    '
Lfx a