This is documentation for Mathematica 3, which was
based on an earlier version of the Wolfram Language.
 Listable Listable is an attribute that can be assigned to a symbol f to indicate that the function f should automatically be threaded over lists that appear as its arguments. Listable functions are effectively applied separately to each element in a list, or to corresponding elements in each list if there is more than one list. Most built-in mathematical functions are Listable. Example: Log is Listable. Log[ a,b,c ]. All the arguments which are lists in a Listable function must be of the same length. Arguments that are not lists are copied as many times as there are elements in the lists. Example: Plus is Listable. a, b, c + x. See the Mathematica book: Section 2.5.3. See also: Thread, Map, Sequence. Further Examples ff didn't get mapped over the list until it was made listable. In[1]:= Out[1]= In[2]:= In[3]:= Out[3]= This restores ff to be what it was originally. In[4]:= In[5]:= Out[5]=