LIST INDEX

LIST _ _ _ _ _ _ _ _ _ _ _ _ operator

The list operator constructs a list from its arguments.

syntax:

list(<item> {,<item>}*) or list() to construct an empty list.

<item> can be any REDUCE scalar expression, including another list. Left and right curly brackets can also be used instead of the operator list to construct a list.

examples:


liss := list(c,b,c,{xx,yy},3x**2+7x+3,df(sin(2*x),x));
	 


                            2
  LISS := {C,B,C,{XX,YY},3*X  + 7*X + 3,2*COS(2*X)} 


length liss; 

  6 


liss := {c,b,c,{xx,yy},3x**2+7x+3,df(sin(2*x),x)};
	 


                            2
  LISS := {C,B,C,{XX,YY},3*X  + 7*X + 3,2*COS(2*X)} 


emptylis := list(); 

  EMPTYLIS := {} 


a . emptylis; 

  {A}

Lists are ordered, hierarchical structures. The elements stay wher e you put them, and only change position in the list if you specifically change them. Lists can have nested sublists to any (reasonable) level. The part operator can be used to access elements anywhere within a list hierarchy. The length operator counts the number of top-level elements of its list argument; elements that are themselves lists still only count as one element.