  
  [1X2 [33X[0;0YPrinting Lists and Iterators[133X[101X
  
  
  [1X2.1 [33X[0;0YPrinting selected items[133X[101X
  
  [33X[0;0YThe  functions  described  here print lists or objects with an iterator with
  one item per line, either the whole list/iterator or certain subsets:[133X
  
  [30X    [33X[0;6Yby giving a list of positions of items to be printed, or[133X
  
  [30X    [33X[0;6Yby specifying a first item and then a regular step.[133X
  
  [1X2.1-1 PrintOneItemPerLine[101X
  
  [33X[1;0Y[29X[2XPrintOneItemPerLine[102X( [3Xobj[103X ) [32X function[133X
  
  [33X[0;0YThis  function  calls  operations  [10XPrintListOneItemPerLine[110X  (which  has been
  transferred from package [5XXMod[105X) or [10XPrintIteratorOneItemPerLine[110X.[133X
  
  [33X[0;0YPrinting  lists vertically, rather than horizontally, may be useful when the
  entries  are  lengthy.  This  function  does  this for lists, iterators, and
  objects which have an iterator.[133X
  
  [4X[32X  Example  [32X[104X
    [4X[28X[128X[104X
    [4X[25Xgap>[125X [27Xs3 := SymmetricGroup( 3 );; [127X[104X
    [4X[25Xgap>[125X [27XL := KnownPropertiesOfObject( GeneratorsOfGroup( s3 ) );;[127X[104X
    [4X[25Xgap>[125X [27XPrintOneItemPerLine( L );[127X[104X
    [4X[28X[ IsFinite,[128X[104X
    [4X[28X  IsSmallList,[128X[104X
    [4X[28X  IsGeneratorsOfMagmaWithInverses,[128X[104X
    [4X[28X  IsGeneratorsOfSemigroup,[128X[104X
    [4X[28X  IsSubsetLocallyFiniteGroup ][128X[104X
    [4X[25Xgap>[125X [27XPrintOneItemPerLine( s3 ); [127X[104X
    [4X[28X()[128X[104X
    [4X[28X(2,3)[128X[104X
    [4X[28X(1,3)[128X[104X
    [4X[28X(1,3,2)[128X[104X
    [4X[28X(1,2,3)[128X[104X
    [4X[28X(1,2)[128X[104X
    [4X[28X[128X[104X
  [4X[32X[104X
  
  [1X2.1-2 PrintSelection[101X
  
  [33X[1;0Y[29X[2XPrintSelection[102X( [3Xobj[103X, [3Xfirst[103X, [3Xstep[103X[, [3Xlast[103X] ) [32X function[133X
  [33X[1;0Y[29X[2XPrintSelection[102X( [3Xobj[103X, [3Xlist[103X ) [32X function[133X
  
  [33X[0;0YThis   function,   given   three  (or  four)  parameters,  calls  operations
  [10XPrintSelectionFromList[110X  or [10XPrintSelectionFromIterator[110X which prints the [13Xfirst[113X
  item  specified,  and  then  the item at every [13Xstep[113X. The fourth parameter is
  essential when the object being printed is infinite.[133X
  
  [33X[0;0YAlternatively,  given  two parameters, with the second parameter a list [10XL[110X of
  positive integers, only the items at positions in [10XL[110X are printed.[133X
  
  [4X[32X  Example  [32X[104X
    [4X[28X[128X[104X
    [4X[25Xgap>[125X [27XL := List( [1..20], n -> n^5 );; [127X[104X
    [4X[25Xgap>[125X [27XPrintSelection( L, 1, 8 );[127X[104X
    [4X[28X1 : 1[128X[104X
    [4X[28X9 : 59049[128X[104X
    [4X[28X17 : 1419857[128X[104X
    [4X[25Xgap>[125X [27XPrintSelection( L, [9..11] );[127X[104X
    [4X[28X9 : 59049[128X[104X
    [4X[28X10 : 100000[128X[104X
    [4X[28X11 : 161051[128X[104X
    [4X[25Xgap>[125X [27Xs5 := SymmetricGroup( 5 );; [127X[104X
    [4X[25Xgap>[125X [27XPrintSelection( s5, 12, 30 );[127X[104X
    [4X[28X12 : (2,5)(3,4)[128X[104X
    [4X[28X42 : (1,5,2,3,4)[128X[104X
    [4X[28X72 : (1,2,4,3)[128X[104X
    [4X[28X102 : (1,4,3,5)[128X[104X
    [4X[25Xgap>[125X [27XPrintSelection( s5, [118..122] );[127X[104X
    [4X[28X118 : (1,4,3,2,5)[128X[104X
    [4X[28X119 : (1,4,2,5,3)[128X[104X
    [4X[28X120 : (1,4,3)(2,5)[128X[104X
    [4X[25Xgap>[125X [27Xf2 := FreeGroup( 2 );; [127X[104X
    [4X[25Xgap>[125X [27XPrintSelection( f2, 20, 20, 100 ); [127X[104X
    [4X[28X20 : f2*f1^2[128X[104X
    [4X[28X40 : f2*f1*f2[128X[104X
    [4X[28X60 : f1*f2*f1^2[128X[104X
    [4X[28X80 : (f2*f1)^2[128X[104X
    [4X[28X100 : f1*f2^2*f1^-1[128X[104X
    [4X[25Xgap>[125X [27XPrintSelection( f2, [11..15] );[127X[104X
    [4X[28X11 : f2^-1*f1^-1[128X[104X
    [4X[28X12 : f1*f2[128X[104X
    [4X[28X13 : f1^-1*f2[128X[104X
    [4X[28X14 : f1*f2^-1[128X[104X
    [4X[28X15 : f1^-1*f2^-1[128X[104X
    [4X[28X[128X[104X
  [4X[32X[104X
  
