# HG changeset patch
# User Nathann Cohen
# Date 1371650805 7200
# Node ID 485c2dca961af9c64498a8ef30d6ccc994ef87f4
# Parent 6858c13cedd15127ffe9381e060a1ad761893a17
Adding Method for testing avoidance in posets  fixed reference in the docstring
diff git a/sage/combinat/posets/posets.py b/sage/combinat/posets/posets.py
 a/sage/combinat/posets/posets.py
+++ b/sage/combinat/posets/posets.py
@@ 1543,11 +1543,10 @@
If ``m`` is a tuple of pairs of chain lengths, returns ``True`` if the poset
does not contain a pair of incomparable chains whose lengths comprise
one of the chain pairs, and ``False`` if not.

A poset is `(m+n)`free if it contains no induced subposet that is
isomorphic to the poset consisting of two disjoint chains of lengths
`m` and `n`. See, for example, Exercise 15 in Chapter 3 of
 Stanley, *Enumerative Combinatorics, Volume 1*, 2nd edition.
+ [EnumComb1]_.
INPUT:
@@ 1619,6 +1618,13 @@
AUTHOR:
 Eric Rowland (20130528)
+
+ REFERENCES:
+
+ .. [EnumComb1] Enumerative Combinatorics I,
+ Second Edition,
+ Richard P. Stanley,
+ Cambridge University Press (2011)
"""
if n is None:
try: