diff --git a/VERSION b/VERSION
index e4d41db..d4e5069 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-5.5.2
+5.5.3
diff --git a/retin3s b/retin3s
index 3f1d57d..0595117 100755
--- a/retin3s
+++ b/retin3s
@@ -1,6 +1,6 @@
 #!/bin/bash
-export prolog=${prolog:=tpl}
-export retina=$(dirname "$(readlink -f "$0")")/retina.pl
+export PROLOG=${PROLOG:=tpl}
+export RETINA=$(dirname "$(readlink -f "$0")")/retina.pl
 
 if [ "$1" == "" ]; then
     echo "usage: $0 file"
@@ -11,7 +11,7 @@ TMPDIR=$(mktemp -d)
 
 eye --nope --quiet --no-bnode-relabeling --ignore-inference-fuse $1 --intermediate ${TMPDIR}/program.n3p
 
-$prolog -g run $retina ${TMPDIR}/program.n3p > ${TMPDIR}/result.pl
+${PROLOG} -g run ${RETINA} ${TMPDIR}/program.n3p > ${TMPDIR}/result.pl
 
 eye --nope --quiet --pass --n3p ${TMPDIR}/result.pl 2> /dev/null
 
diff --git a/retina b/retina
index c0129de..72f7063 100755
--- a/retina
+++ b/retina
@@ -1,5 +1,5 @@
 #!/bin/bash
-export prolog=${prolog:=tpl}
-export retina=$(dirname "$(readlink -f "$0")")/retina.pl
+export PROLOG=${PROLOG:=tpl}
+export RETINA=$(dirname "$(readlink -f "$0")")/retina.pl
 
-$prolog -g run $retina "$@"
+${PROLOG} -g run ${RETINA} "$@"
diff --git a/retina.pl b/retina.pl
index 9e7ae74..72eb07f 100644
--- a/retina.pl
+++ b/retina.pl
@@ -21,12 +21,11 @@
 :- dynamic(recursion/1).
 :- dynamic(skolem/2).
 :- dynamic(uuid/2).
-:- dynamic('<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>'/2).
 :- dynamic('<http://www.w3.org/2000/10/swap/log#onNegativeSurface>'/2).
 :- dynamic('<http://www.w3.org/2000/10/swap/log#onNegativeComponentSurface>'/2).
 :- dynamic('<http://www.w3.org/2000/10/swap/log#onNegativeAnswerSurface>'/2).
 
-version_info('retina v5.5.2 (2024-07-02)').
+version_info('retina v5.5.3 (2024-07-03)').
 
 % run
 run :-
diff --git a/test b/test
index c0b6297..6eb7372 100755
--- a/test
+++ b/test
@@ -13,8 +13,8 @@ echo -e "${YELLOW}Running retina/test${NORMAL}"
 echo -e "${YELLOW}-------------------${NORMAL}"
 echo ""
 
-export prolog="${1:-tpl}"
-export retina=`pwd`/retina.pl
+export PROLOG="${1:-tpl}"
+export RETINA=`pwd`/retina.pl
 
 pad () {
     [ "$#" -gt 1 ]