This is documentation for Mathematica 6, which was
based on an earlier version of the Wolfram Language.

# Position

 Position[expr, pattern]gives a list of the positions at which objects matching pattern appear in expr. Position[expr, pattern, levelspec]finds only objects that appear on levels specified by levelspec. Position[expr, pattern, levelspec, n]gives the positions of the first n objects found.
• Position[expr, pattern] tests all the subparts of expr in turn to try and find ones that match pattern.
• A part specification {} returned by Position represents the whole of expr.
• Position[list, pattern, {1}, Heads->False] finds positions only of objects that appear as complete elements of list.
• Position uses standard level specifications:
 n levels 1 through n Infinity levels 1 through Infinity {n} level n only {n1,n2} levels n1 through n2
• A positive level n consists of all parts of expr specified by n indices.
• A negative level -n consists of all parts of expr with depth n.
• Level 0 corresponds to the whole expression.
• With the default option setting , Position includes heads of expressions, and their parts.
• Position traverses expressions in depth-first order, yielding lists of indices in lexicographic order.
Find the positions at which b occurs:
 Out[1]=
 Out[2]=

Find all positions at which x to any power appears:
 Out[1]=
Find only those down to level 2:
 Out[2]=
 Scope   (2)
 Options   (1)
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