diff --git a/docs/yap.tex b/docs/yap.tex
index 5f64659a8..c155b1f0d 100644
--- a/docs/yap.tex
+++ b/docs/yap.tex
@@ -6586,6 +6586,12 @@ stable, that is, if you insert several pairs with the same @var{Key} it
 is not defined which of them will come out first, and it is possible for
 any of them to come out first depending on the  history of the heap.
 
+@item empty_heap(?@var{Heap})
+@findex empty_heap/1
+@syindex        empty_heap/1
+@cnindex        empty_heap/1
+Succeeds if @var{Heap} is an empty heap.
+
 @item get_from_heap(+@var{Heap},-@var{key},-@var{Datum},-@var{Heap})
 @findex get_from_heap/4
 @syindex        get_from_heap/4
diff --git a/library/heaps.yap b/library/heaps.yap
index f13771c1d..cf4cae0a8 100644
--- a/library/heaps.yap
+++ b/library/heaps.yap
@@ -43,6 +43,7 @@
 :- module(heaps,[
 	add_to_heap/4,		%   Heap x Key x Datum -> Heap
 	get_from_heap/4,	%   Heap -> Key x Datum x Heap
+	empty_heap/1,            %   Heap
 	heap_size/2,		%   Heap -> Size
 	heap_to_list/2,		%   Heap -> List
 	list_to_heap/2,		%   List -> Heap
@@ -95,7 +96,7 @@ add_to_heap(t(M,[H|T],OldTree), Key, Datum, t(N,T,NewTree)) :-
 add_to_heap(1, Key, Datum, _, t(Key,Datum,t,t)) :- !.
 add_to_heap(N, Key, Datum, t(K1,D1,L1,R1), t(K2,D2,L2,R2)) :-
 	E is N mod 2,
-	M is N/2,
+	M is N//2,
     %   M > 0,		%  only called from list_to_heap/4,add_to_heap/4
 	sort2(Key, Datum, K1, D1, K2, D2, K3, D3),
 	add_to_heap(E, M, K3, D3, L1, R1, L2, R2).
@@ -227,3 +228,6 @@ min_of_heap(t(Ka,Da,_,_), t(Kb,Db,_,_), Kb, Db) :-
 min_of_heap(t(Ka,Da,_,_), _, Ka, Da).
 min_of_heap(t, t(Kb,Db,_,_), Kb, Db).
 
+empty_heap(t(0,[],t)).
+
+