From 5db8e25735016fa84bc7a56579bc255965a86d87 Mon Sep 17 00:00:00 2001
From: Vitor Santos Costa <vsc@dcc.fc.up.pt>
Date: Sun, 31 Jul 2016 10:33:20 -0500
Subject: [PATCH] must be early for boot

---
 pl/bootutils.yap | 36 ++++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)
 create mode 100644 pl/bootutils.yap

diff --git a/pl/bootutils.yap b/pl/bootutils.yap
new file mode 100644
index 000000000..a5f1e6c9a
--- /dev/null
+++ b/pl/bootutils.yap
@@ -0,0 +1,36 @@
+/** @pred  recordaifnot(+ _K_, _T_,- _R_) 
+
+
+If a term equal to  _T_ up to variable renaming is stored under key
+ _K_ fail. Otherwise, make term  _T_ the first record under key
+ _K_ and unify  _R_ with its reference.
+
+ 
+*/
+recordaifnot(K,T,R) :-
+        recorded(K,T,R), % force non-det binding to R.
+        '$still_variant'(R,T),
+        !,
+        fail.
+recordaifnot(K,T,R) :-
+        recorda(K,T,R).
+
+/** @pred  recordzifnot(+ _K_, _T_,- _R_) 
+
+
+If a term equal to  _T_ up to variable renaming is stored under key
+ _K_ fail. Otherwise, make term  _T_ the first record under key
+ _K_ and unify  _R_ with its reference.
+
+This predicate is YAP specific.
+
+ 
+*/
+recordzifnot(K,T,R) :-
+        recorded(K,T,R),
+        '$still_variant'(R,T),
+        !,
+        fail.
+recordzifnot(K,T,R) :-
+        recordz(K,T,R).
+