Execution Chart

We display below the execution chart for this examination (boot time has been removed).

Trace from the execution

Formatting '/data/fkordon/mcc2023-input.r491-tall-167912710800703.qcow2', fmt=qcow2 size=4294967296 backing_file=/data/fkordon/mcc2023-input.qcow2 cluster_size=65536 lazy_refcounts=off refcount_bits=16
Waiting for the VM to be ready (probing ssh)
......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................
=====================================================================
Generated by BenchKit 2-5348
Executing tool smartxred
Input is TokenRing-PT-050, examination is ReachabilityFireability
Time confinement is 3600 seconds
Memory confinement is 16384 MBytes
Number of cores is 4
Run identifier is r491-tall-167912710800703
=====================================================================

--------------------
preparation of the directory to be used:
/home/mcc/execution
total 1.6G
-rw-r--r-- 1 mcc users 1.7M Feb 26 14:35 CTLCardinality.txt
-rw-r--r-- 1 mcc users 7.4M Feb 26 14:35 CTLCardinality.xml
-rw-r--r-- 1 mcc users 72M Feb 26 12:03 CTLFireability.txt
-rw-r--r-- 1 mcc users 255M Feb 26 11:17 CTLFireability.xml
-rw-r--r-- 1 mcc users 4.2K Jan 29 11:41 GenericPropertiesDefinition.xml
-rw-r--r-- 1 mcc users 6.6K Jan 29 11:41 GenericPropertiesVerdict.xml
-rw-r--r-- 1 mcc users 1.6M Feb 25 17:21 LTLCardinality.txt
-rw-r--r-- 1 mcc users 5.5M Feb 25 17:21 LTLCardinality.xml
-rw-r--r-- 1 mcc users 27M Feb 25 17:21 LTLFireability.txt
-rw-r--r-- 1 mcc users 73M Feb 25 17:21 LTLFireability.xml
-rw-r--r-- 1 mcc users 2.7M Feb 28 13:24 ReachabilityCardinality.txt
-rw-r--r-- 1 mcc users 13M Feb 28 13:24 ReachabilityCardinality.xml
-rw-r--r-- 1 mcc users 241M Feb 28 12:52 ReachabilityFireability.txt
-rw-r--r-- 1 mcc users 850M Feb 28 11:23 ReachabilityFireability.xml
-rw-r--r-- 1 mcc users 279K Feb 25 17:21 UpperBounds.txt
-rw-r--r-- 1 mcc users 707K Feb 25 17:21 UpperBounds.xml
-rw-r--r-- 1 mcc users 5 Mar 5 18:23 equiv_col
-rw-r--r-- 1 mcc users 4 Mar 5 18:23 instance
-rw-r--r-- 1 mcc users 6 Mar 5 18:23 iscolored
-rw-r--r-- 1 mcc users 61M Mar 5 18:23 model.pnml

--------------------
content from stdout:

=== Data for post analysis generated by BenchKit (invocation template)

The expected result is a vector of booleans
BOOL_VECTOR

here is the order used to build the result vector(from text file)
FORMULA_NAME TokenRing-PT-050-ReachabilityFireability-00
FORMULA_NAME TokenRing-PT-050-ReachabilityFireability-01
FORMULA_NAME TokenRing-PT-050-ReachabilityFireability-02
FORMULA_NAME TokenRing-PT-050-ReachabilityFireability-03
FORMULA_NAME TokenRing-PT-050-ReachabilityFireability-04
FORMULA_NAME TokenRing-PT-050-ReachabilityFireability-05
FORMULA_NAME TokenRing-PT-050-ReachabilityFireability-06
FORMULA_NAME TokenRing-PT-050-ReachabilityFireability-07
FORMULA_NAME TokenRing-PT-050-ReachabilityFireability-08
FORMULA_NAME TokenRing-PT-050-ReachabilityFireability-09
FORMULA_NAME TokenRing-PT-050-ReachabilityFireability-10
FORMULA_NAME TokenRing-PT-050-ReachabilityFireability-11
FORMULA_NAME TokenRing-PT-050-ReachabilityFireability-12
FORMULA_NAME TokenRing-PT-050-ReachabilityFireability-13
FORMULA_NAME TokenRing-PT-050-ReachabilityFireability-14
FORMULA_NAME TokenRing-PT-050-ReachabilityFireability-15

=== Now, execution of the tool begins

BK_START 1679285659208

bash -c /home/mcc/BenchKit/BenchKit_head.sh 2> STDERR ; echo ; echo -n "BK_STOP " ; date -u +%s%3N
Invoking MCC driver with
BK_TOOL=smartxred
BK_EXAMINATION=ReachabilityFireability
BK_BIN_PATH=/home/mcc/BenchKit/bin/
BK_TIME_CONFINEMENT=3600
BK_INPUT=TokenRing-PT-050
Applying reductions before tool smart
Invoking reducer
Running Version 202303021504
[2023-03-20 04:14:24] [INFO ] Running its-tools with arguments : [-pnfolder, /home/mcc/execution, -examination, ReachabilityFireability, -timeout, 360, -rebuildPNML]
[2023-03-20 04:14:24] [INFO ] Parsing pnml file : /home/mcc/execution/model.pnml
[2023-03-20 04:14:27] [INFO ] Load time of PNML (sax parser for PT used): 3171 ms
[2023-03-20 04:14:27] [INFO ] Transformed 2601 places.
[2023-03-20 04:14:28] [INFO ] Transformed 127551 transitions.
[2023-03-20 04:14:28] [INFO ] Parsed PT model containing 2601 places and 127551 transitions and 510204 arcs in 3663 ms.
Parsed 16 properties from file /home/mcc/execution/ReachabilityFireability.xml in 10931 ms.
Working with output stream class java.io.PrintStream
FORMULA TokenRing-PT-050-ReachabilityFireability-05 TRUE TECHNIQUES TOPOLOGICAL INITIAL_STATE
FORMULA TokenRing-PT-050-ReachabilityFireability-06 TRUE TECHNIQUES TOPOLOGICAL INITIAL_STATE
Interrupted random walk after 4178 steps, including 1 resets, run timeout after 30010 ms. (steps per millisecond=0 ) properties seen 3
FORMULA TokenRing-PT-050-ReachabilityFireability-04 FALSE TECHNIQUES TOPOLOGICAL RANDOM_WALK
FORMULA TokenRing-PT-050-ReachabilityFireability-02 FALSE TECHNIQUES TOPOLOGICAL RANDOM_WALK
FORMULA TokenRing-PT-050-ReachabilityFireability-01 FALSE TECHNIQUES TOPOLOGICAL RANDOM_WALK
Interrupted Best-First random walk after 291 steps, including 0 resets, run timeout after 5376 ms. (steps per millisecond=0 ) properties seen 0
Interrupted Best-First random walk after 101 steps, including 0 resets, run timeout after 6245 ms. (steps per millisecond=0 ) properties seen 0
Interrupted Best-First random walk after 150 steps, including 0 resets, run timeout after 5532 ms. (steps per millisecond=0 ) properties seen 0
Interrupted Best-First random walk after 9779 steps, including 2 resets, run timeout after 5005 ms. (steps per millisecond=1 ) properties seen 0
Incomplete Best-First random walk after 10001 steps, including 2 resets, run finished after 1478 ms. (steps per millisecond=6 ) properties (out of 11) seen :1
FORMULA TokenRing-PT-050-ReachabilityFireability-14 FALSE TECHNIQUES TOPOLOGICAL BESTFIRST_WALK
Incomplete Best-First random walk after 10001 steps, including 2 resets, run finished after 1568 ms. (steps per millisecond=6 ) properties (out of 10) seen :0
Incomplete Best-First random walk after 10000 steps, including 2 resets, run finished after 783 ms. (steps per millisecond=12 ) properties (out of 10) seen :0
Incomplete Best-First random walk after 10001 steps, including 2 resets, run finished after 311 ms. (steps per millisecond=32 ) properties (out of 10) seen :0
Incomplete Best-First random walk after 10000 steps, including 2 resets, run finished after 3980 ms. (steps per millisecond=2 ) properties (out of 10) seen :0
Incomplete Best-First random walk after 10001 steps, including 2 resets, run finished after 510 ms. (steps per millisecond=19 ) properties (out of 10) seen :0
Running SMT prover for 10 properties.
// Phase 1: matrix 127551 rows 2601 cols
[2023-03-20 04:15:46] [INFO ] Computed 51 place invariants in 509 ms
[2023-03-20 04:16:07] [INFO ] [Real]Absence check using 51 positive place invariants in 92 ms returned sat
java.lang.RuntimeException: SMT solver raised an error when submitting script. Raised (error "Error writing to Z3 solver: java.io.IOException: Stream closed...
at fr.lip6.move.gal.structural.smt.SMTUtils.execAndCheckResult(SMTUtils.java:251)
at fr.lip6.move.gal.structural.smt.DeadlockTester.verifyPossible(DeadlockTester.java:629)
at fr.lip6.move.gal.structural.smt.DeadlockTester.testUnreachableWithSMTIncremental(DeadlockTester.java:339)
at fr.lip6.move.gal.structural.smt.DeadlockTester.testUnreachableWithSMT(DeadlockTester.java:223)
at fr.lip6.move.gal.application.solver.ReachabilitySolver.applyReductions(ReachabilitySolver.java:95)
at fr.lip6.move.gal.application.Application.startNoEx(Application.java:902)
at fr.lip6.move.gal.application.Application.start(Application.java:178)
at fr.lip6.move.gal.itscl.application.Application.start(Application.java:45)
at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:203)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:136)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:104)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:402)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:255)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:568)
at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:659)
at org.eclipse.equinox.launcher.Main.basicRun(Main.java:596)
at org.eclipse.equinox.launcher.Main.run(Main.java:1467)
at org.eclipse.equinox.launcher.Main.main(Main.java:1440)
[2023-03-20 04:16:12] [WARNING] SMT solver failed with error :SMT solver raised an error when submitting script.... while checking expressions.
[2023-03-20 04:16:12] [INFO ] After 25063ms SMT Verify possible using all constraints in real domain returned unsat :0 sat :0
Fused 10 Parikh solutions to 1 different solutions.
Parikh walk visited 0 properties in 0 ms.
Support contains 2601 out of 2601 places. Attempting structural reductions.
Starting structural reductions in REACHABILITY mode, iteration 0 : 2601/2601 places, 127551/127551 transitions.
Applied a total of 0 rules in 900 ms. Remains 2601 /2601 variables (removed 0) and now considering 127551/127551 (removed 0) transitions.
Finished structural reductions in REACHABILITY mode , in 1 iterations and 914 ms. Remains : 2601/2601 places, 127551/127551 transitions.
Interrupted random walk after 4876 steps, including 1 resets, run timeout after 30009 ms. (steps per millisecond=0 ) properties seen 0
Interrupted Best-First random walk after 291 steps, including 0 resets, run timeout after 5404 ms. (steps per millisecond=0 ) properties seen 0
Interrupted Best-First random walk after 101 steps, including 0 resets, run timeout after 6073 ms. (steps per millisecond=0 ) properties seen 0
Interrupted Best-First random walk after 150 steps, including 0 resets, run timeout after 6467 ms. (steps per millisecond=0 ) properties seen 0
Incomplete Best-First random walk after 10000 steps, including 2 resets, run finished after 3926 ms. (steps per millisecond=2 ) properties (out of 10) seen :0
Incomplete Best-First random walk after 10000 steps, including 2 resets, run finished after 2290 ms. (steps per millisecond=4 ) properties (out of 10) seen :0
Incomplete Best-First random walk after 10001 steps, including 2 resets, run finished after 636 ms. (steps per millisecond=15 ) properties (out of 10) seen :0
Incomplete Best-First random walk after 10001 steps, including 2 resets, run finished after 464 ms. (steps per millisecond=21 ) properties (out of 10) seen :0
Incomplete Best-First random walk after 10000 steps, including 2 resets, run finished after 2796 ms. (steps per millisecond=3 ) properties (out of 10) seen :0
Incomplete Best-First random walk after 10001 steps, including 2 resets, run finished after 1320 ms. (steps per millisecond=7 ) properties (out of 10) seen :0
Incomplete Best-First random walk after 10001 steps, including 2 resets, run finished after 741 ms. (steps per millisecond=13 ) properties (out of 10) seen :0
Interrupted probabilistic random walk after 66502 steps, run timeout after 180004 ms. (steps per millisecond=0 ) properties seen :{}
Probabilistic random walk after 66502 steps, saw 20766 distinct states, run finished after 180007 ms. (steps per millisecond=0 ) properties seen :0
Running SMT prover for 10 properties.
[2023-03-20 04:20:15] [INFO ] Invariant cache hit.
[2023-03-20 04:20:35] [INFO ] [Real]Absence check using 51 positive place invariants in 88 ms returned sat
java.lang.RuntimeException: SMT solver raised an error when submitting script. Raised (error "Failed to assert expression: java.io.IOException: Stream close...
at fr.lip6.move.gal.structural.smt.SMTUtils.execAndCheckResult(SMTUtils.java:251)
at fr.lip6.move.gal.structural.smt.DeadlockTester.verifyPossible(DeadlockTester.java:629)
at fr.lip6.move.gal.structural.smt.DeadlockTester.testUnreachableWithSMTIncremental(DeadlockTester.java:339)
at fr.lip6.move.gal.structural.smt.DeadlockTester.testUnreachableWithSMT(DeadlockTester.java:223)
at fr.lip6.move.gal.application.solver.ReachabilitySolver.applyReductions(ReachabilitySolver.java:95)
at fr.lip6.move.gal.application.Application.startNoEx(Application.java:902)
at fr.lip6.move.gal.application.Application.start(Application.java:178)
at fr.lip6.move.gal.itscl.application.Application.start(Application.java:45)
at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:203)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:136)
at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:104)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:402)
at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:255)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:568)
at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:659)
at org.eclipse.equinox.launcher.Main.basicRun(Main.java:596)
at org.eclipse.equinox.launcher.Main.run(Main.java:1467)
at org.eclipse.equinox.launcher.Main.main(Main.java:1440)
[2023-03-20 04:20:40] [WARNING] SMT solver failed with error :SMT solver raised an error when submitting script.... while checking expressions.
[2023-03-20 04:20:40] [INFO ] After 25021ms SMT Verify possible using all constraints in real domain returned unsat :0 sat :0
Fused 10 Parikh solutions to 1 different solutions.
Parikh walk visited 0 properties in 0 ms.
Support contains 2601 out of 2601 places. Attempting structural reductions.
Starting structural reductions in REACHABILITY mode, iteration 0 : 2601/2601 places, 127551/127551 transitions.
Applied a total of 0 rules in 689 ms. Remains 2601 /2601 variables (removed 0) and now considering 127551/127551 (removed 0) transitions.
Finished structural reductions in REACHABILITY mode , in 1 iterations and 689 ms. Remains : 2601/2601 places, 127551/127551 transitions.
Starting structural reductions in REACHABILITY mode, iteration 0 : 2601/2601 places, 127551/127551 transitions.
Applied a total of 0 rules in 689 ms. Remains 2601 /2601 variables (removed 0) and now considering 127551/127551 (removed 0) transitions.
[2023-03-20 04:20:42] [INFO ] Invariant cache hit.
[2023-03-20 04:20:42] [INFO ] Implicit Places using invariants in 391 ms returned []
Implicit Place search using SMT only with invariants took 393 ms to find 0 implicit places.
[2023-03-20 04:20:42] [INFO ] Invariant cache hit.
[2023-03-20 04:21:12] [INFO ] Performed 65867/127551 'is it Dead' test of which 0 returned DEAD in 30 seconds.
[2023-03-20 04:21:41] [INFO ] Dead Transitions using invariants and state equation in 58750 ms found 0 transitions.
Finished structural reductions in REACHABILITY mode , in 1 iterations and 59848 ms. Remains : 2601/2601 places, 127551/127551 transitions.
[2023-03-20 04:21:44] [INFO ] Export to MCC of 10 properties in file /home/mcc/execution/ReachabilityFireability.sr.xml took 1210 ms.
[2023-03-20 04:21:44] [INFO ] Export to PNML in file /home/mcc/execution/model.sr.pnml of net with 2601 places, 127551 transitions and 510204 arcs took 260 ms.
[2023-03-20 04:21:53] [INFO ] Flatten gal took : 5465 ms
Total runtime 449295 ms.
There are residual formulas that ITS could not solve within timeout
======================================================
========== this is Smart for the MCC'2018 ============
======================================================
Running TokenRing (PT), instance 050
Examination ReachabilityFireability
Parser /home/mcc/BenchKit/bin//../reducer/bin//../../smart/bin//parser/Fireability.jar
Model checker /home/mcc/BenchKit/bin//../reducer/bin//../../smart/bin//rem_exec//smart

GOT IT HERE. BS
Petri model created: 2601 places, 127551 transitions, 510204 arcs.
TIME LIMIT: Killed by timeout after 3600 seconds
MemTotal: 16393216 kB
MemFree: 12204392 kB
After kill :
MemTotal: 16393216 kB
MemFree: 13760880 kB

BK_TIME_CONFINEMENT_REACHED

--------------------
content from stderr:

+ ulimit -s 65536
+ [[ -z '' ]]
+ export LTSMIN_MEM_SIZE=8589934592
+ LTSMIN_MEM_SIZE=8589934592
+ export PYTHONPATH=/home/mcc/BenchKit/itstools/pylibs
+ PYTHONPATH=/home/mcc/BenchKit/itstools/pylibs
+ export LD_LIBRARY_PATH=/home/mcc/BenchKit/itstools/pylibs:
+ LD_LIBRARY_PATH=/home/mcc/BenchKit/itstools/pylibs:
++ sed s/.jar//
++ perl -pe 's/.*\.//g'
++ ls /home/mcc/BenchKit/bin//../reducer/bin//../../itstools//itstools/plugins/fr.lip6.move.gal.application.pnmcc_1.0.0.202303021504.jar
+ VERSION=202303021504
+ echo 'Running Version 202303021504'
+ /home/mcc/BenchKit/bin//../reducer/bin//../../itstools//itstools/its-tools -pnfolder /home/mcc/execution -examination ReachabilityFireability -timeout 360 -rebuildPNML

Sequence of Actions to be Executed by the VM

This is useful if one wants to reexecute the tool in the VM from the submitted image disk.

set -x
# this is for BenchKit: configuration of major elements for the test
export BK_INPUT="TokenRing-PT-050"
export BK_EXAMINATION="ReachabilityFireability"
export BK_TOOL="smartxred"
export BK_RESULT_DIR="/tmp/BK_RESULTS/OUTPUTS"
export BK_TIME_CONFINEMENT="3600"
export BK_MEMORY_CONFINEMENT="16384"
export BK_BIN_PATH="/home/mcc/BenchKit/bin/"

# this is specific to your benchmark or test

export BIN_DIR="$HOME/BenchKit/bin"

# remove the execution directoty if it exists (to avoid increse of .vmdk images)
if [ -d execution ] ; then
rm -rf execution
fi

# this is for BenchKit: explicit launching of the test
echo "====================================================================="
echo " Generated by BenchKit 2-5348"
echo " Executing tool smartxred"
echo " Input is TokenRing-PT-050, examination is ReachabilityFireability"
echo " Time confinement is $BK_TIME_CONFINEMENT seconds"
echo " Memory confinement is 16384 MBytes"
echo " Number of cores is 4"
echo " Run identifier is r491-tall-167912710800703"
echo "====================================================================="
echo
echo "--------------------"
echo "preparation of the directory to be used:"

tar xzf /home/mcc/BenchKit/INPUTS/TokenRing-PT-050.tgz
mv TokenRing-PT-050 execution
cd execution
if [ "ReachabilityFireability" = "ReachabilityDeadlock" ] || [ "ReachabilityFireability" = "UpperBounds" ] || [ "ReachabilityFireability" = "QuasiLiveness" ] || [ "ReachabilityFireability" = "StableMarking" ] || [ "ReachabilityFireability" = "Liveness" ] || [ "ReachabilityFireability" = "OneSafe" ] || [ "ReachabilityFireability" = "StateSpace" ]; then
rm -f GenericPropertiesVerdict.xml
fi
pwd
ls -lh

echo
echo "--------------------"
echo "content from stdout:"
echo
echo "=== Data for post analysis generated by BenchKit (invocation template)"
echo
if [ "ReachabilityFireability" = "UpperBounds" ] ; then
echo "The expected result is a vector of positive values"
echo NUM_VECTOR
elif [ "ReachabilityFireability" != "StateSpace" ] ; then
echo "The expected result is a vector of booleans"
echo BOOL_VECTOR
else
echo "no data necessary for post analysis"
fi
echo
if [ -f "ReachabilityFireability.txt" ] ; then
echo "here is the order used to build the result vector(from text file)"
for x in $(grep Property ReachabilityFireability.txt | cut -d ' ' -f 2 | sort -u) ; do
echo "FORMULA_NAME $x"
done
elif [ -f "ReachabilityFireability.xml" ] ; then # for cunf (txt files deleted;-)
echo echo "here is the order used to build the result vector(from xml file)"
for x in $(grep '' ReachabilityFireability.xml | cut -d '>' -f 2 | cut -d '<' -f 1 | sort -u) ; do
echo "FORMULA_NAME $x"
done
elif [ "ReachabilityFireability" = "ReachabilityDeadlock" ] || [ "ReachabilityFireability" = "QuasiLiveness" ] || [ "ReachabilityFireability" = "StableMarking" ] || [ "ReachabilityFireability" = "Liveness" ] || [ "ReachabilityFireability" = "OneSafe" ] ; then
echo "FORMULA_NAME ReachabilityFireability"
fi
echo
echo "=== Now, execution of the tool begins"
echo
echo -n "BK_START "
date -u +%s%3N
echo
timeout -s 9 $BK_TIME_CONFINEMENT bash -c "/home/mcc/BenchKit/BenchKit_head.sh 2> STDERR ; echo ; echo -n \"BK_STOP \" ; date -u +%s%3N"
if [ $? -eq 137 ] ; then
echo
echo "BK_TIME_CONFINEMENT_REACHED"
fi
echo
echo "--------------------"
echo "content from stderr:"
echo
cat STDERR ;