Execution Chart

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

Trace from the execution

Formatting '/data/fkordon/mcc2019-input.r030-smll-155225127000385.qcow2', fmt=qcow2 size=4294967296 backing_file='/data/fkordon/mcc2019-input.qcow2' encryption=off cluster_size=65536 lazy_refcounts=off
Waiting for the VM to be ready (probing ssh)
......................
=====================================================================
Generated by BenchKit 2-3957
Executing tool itstools
Input is ClientsAndServers-PT-N1000P0, examination is LTLFireability
Time confinement is 3600 seconds
Memory confinement is 16384 MBytes
Number of cores is 4
Run identifier is r030-smll-155225127000385
=====================================================================

--------------------
preparation of the directory to be used:
/home/mcc/execution
total 184K
-rw-r--r-- 1 mcc users 3.9K Feb 9 08:38 CTLCardinality.txt
-rw-r--r-- 1 mcc users 22K Feb 9 08:38 CTLCardinality.xml
-rw-r--r-- 1 mcc users 2.7K Feb 5 07:23 CTLFireability.txt
-rw-r--r-- 1 mcc users 19K Feb 5 07:23 CTLFireability.xml
-rw-r--r-- 1 mcc users 4.0K Mar 10 17:31 GenericPropertiesDefinition.xml
-rw-r--r-- 1 mcc users 6.2K Mar 10 17:31 GenericPropertiesVerdict.xml
-rw-r--r-- 1 mcc users 115 Feb 24 15:05 GlobalProperties.txt
-rw-r--r-- 1 mcc users 353 Feb 24 15:05 GlobalProperties.xml
-rw-r--r-- 1 mcc users 2.5K Feb 4 23:09 LTLCardinality.txt
-rw-r--r-- 1 mcc users 11K Feb 4 23:09 LTLCardinality.xml
-rw-r--r-- 1 mcc users 2.0K Feb 4 22:33 LTLFireability.txt
-rw-r--r-- 1 mcc users 8.4K Feb 4 22:33 LTLFireability.xml
-rw-r--r-- 1 mcc users 3.5K Feb 2 01:47 ReachabilityCardinality.txt
-rw-r--r-- 1 mcc users 17K Feb 2 01:47 ReachabilityCardinality.xml
-rw-r--r-- 1 mcc users 3.0K Jan 29 15:28 ReachabilityFireability.txt
-rw-r--r-- 1 mcc users 19K Jan 29 15:28 ReachabilityFireability.xml
-rw-r--r-- 1 mcc users 1.8K Feb 4 22:18 UpperBounds.txt
-rw-r--r-- 1 mcc users 3.8K Feb 4 22:18 UpperBounds.xml
-rw-r--r-- 1 mcc users 6 Jan 29 09:34 equiv_col
-rw-r--r-- 1 mcc users 8 Jan 29 09:34 instance
-rw-r--r-- 1 mcc users 6 Jan 29 09:34 iscolored
-rw-r--r-- 1 mcc users 9.1K Mar 10 17:31 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 ClientsAndServers-PT-N1000P0-LTLFireability-00
FORMULA_NAME ClientsAndServers-PT-N1000P0-LTLFireability-01
FORMULA_NAME ClientsAndServers-PT-N1000P0-LTLFireability-02
FORMULA_NAME ClientsAndServers-PT-N1000P0-LTLFireability-03
FORMULA_NAME ClientsAndServers-PT-N1000P0-LTLFireability-04
FORMULA_NAME ClientsAndServers-PT-N1000P0-LTLFireability-05
FORMULA_NAME ClientsAndServers-PT-N1000P0-LTLFireability-06
FORMULA_NAME ClientsAndServers-PT-N1000P0-LTLFireability-07
FORMULA_NAME ClientsAndServers-PT-N1000P0-LTLFireability-08
FORMULA_NAME ClientsAndServers-PT-N1000P0-LTLFireability-09
FORMULA_NAME ClientsAndServers-PT-N1000P0-LTLFireability-10
FORMULA_NAME ClientsAndServers-PT-N1000P0-LTLFireability-11
FORMULA_NAME ClientsAndServers-PT-N1000P0-LTLFireability-12
FORMULA_NAME ClientsAndServers-PT-N1000P0-LTLFireability-13
FORMULA_NAME ClientsAndServers-PT-N1000P0-LTLFireability-14
FORMULA_NAME ClientsAndServers-PT-N1000P0-LTLFireability-15

=== Now, execution of the tool begins

BK_START 1552739200165

Working with output stream class java.io.PrintStream
Using solver Z3 to compute partial order matrices.
Built C files in :
/home/mcc/execution
Invoking ITS tools like this :CommandLine [args=[/home/mcc/BenchKit/itstools/plugins/fr.lip6.move.gal.itstools.binaries_1.0.0.201903111103/bin/its-ltl-linux64, --gc-threshold, 2000000, -i, /home/mcc/execution/LTLFireability.pnml.gal, -t, CGAL, -LTL, /home/mcc/execution/LTLFireability.ltl, -c, -stutter-deadlock], workingDir=/home/mcc/execution]

its-ltl command run as :

/home/mcc/BenchKit/itstools/plugins/fr.lip6.move.gal.itstools.binaries_1.0.0.201903111103/bin/its-ltl-linux64 --gc-threshold 2000000 -i /home/mcc/execution/LTLFireability.pnml.gal -t CGAL -LTL /home/mcc/execution/LTLFireability.ltl -c -stutter-deadlock
Read 16 LTL properties
Checking formula 0 : !((F(G(G(G(F("((CA>=1)&&(CwA>=1))")))))))
Formula 0 simplified : !FGF"((CA>=1)&&(CwA>=1))"
Presburger conditions satisfied. Using coverability to approximate state space in K-Induction.
// Phase 1: matrix 18 rows 25 cols
invariant :Uf + SF + CF + -1'CR + MtF + SG + MpG + -1'Si + -2'StR + -2'SwG + -1'SpG + -1'SwA + -1'SpA + Cb + CwG = 2000
invariant :SA + SF + -1'MpG + -1'MwU + -1'Mi + -1'SwA = -3000
invariant :CG + CR + StR + SwG + SpG + -1'CwG = 0
invariant :CwA + Cb + CwG + Ci = 8000
invariant :StF + Si + StR + SwG + SpG + SwA + SpA = 2000
invariant :SR + SG + MpG + MwU + -1'SwG = 0
invariant :CA + CF + -1'Si + -1'StR + -1'SwG + -1'SpG + Cb + CwG + Ci = 6000
invariant :MpA + MtF + MpG + MwU + Mi = 3000
Running compilation step : CommandLine [args=[gcc, -c, -I/home/mcc/BenchKit//lts_install_dir//include, -I., -std=c99, -fPIC, -O2, model.c], workingDir=/home/mcc/execution]
Compilation finished in 531 ms.
Running link step : CommandLine [args=[gcc, -shared, -o, gal.so, model.o], workingDir=/home/mcc/execution]
Link finished in 50 ms.
Running LTSmin : CommandLine [args=[/home/mcc/BenchKit//lts_install_dir//bin/pins2lts-mc, ./gal.so, --threads=8, -p, --pins-guards, --when, --ltl, <>([]([]([](<>((LTLAP0==true)))))), --buchi-type=spotba], workingDir=/home/mcc/execution]
LTSmin run took 2760 ms.
FORMULA ClientsAndServers-PT-N1000P0-LTLFireability-00 FALSE TECHNIQUES PARTIAL_ORDER EXPLICIT LTSMIN SAT_SMT
Running LTSmin : CommandLine [args=[/home/mcc/BenchKit//lts_install_dir//bin/pins2lts-mc, ./gal.so, --threads=8, --when, --ltl, ((LTLAP1==true))U(X(X(<>((LTLAP2==true))))), --buchi-type=spotba], workingDir=/home/mcc/execution]
WARNING : LTS min runner thread failed on error :java.lang.RuntimeException: Unexpected exception when executing ltsmin :CommandLine [args=[/home/mcc/BenchKit//lts_install_dir//bin/pins2lts-mc, ./gal.so, --threads=8, --when, --ltl, ((LTLAP1==true))U(X(X(<>((LTLAP2==true))))), --buchi-type=spotba], workingDir=/home/mcc/execution]
255

BK_TIME_CONFINEMENT_REACHED

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

+ export BINDIR=/home/mcc/BenchKit/
+ BINDIR=/home/mcc/BenchKit/
++ pwd
+ export MODEL=/home/mcc/execution
+ MODEL=/home/mcc/execution
+ [[ LTLFireability = StateSpace ]]
+ /home/mcc/BenchKit//runeclipse.sh /home/mcc/execution LTLFireability -its -ltsminpath /home/mcc/BenchKit//lts_install_dir/ -smt
+ ulimit -s 65536
+ [[ -z '' ]]
+ export LTSMIN_MEM_SIZE=8589934592
+ LTSMIN_MEM_SIZE=8589934592
+ /home/mcc/BenchKit//itstools/its-tools -data /home/mcc/execution/workspace -pnfolder /home/mcc/execution -examination LTLFireability -z3path /home/mcc/BenchKit//z3/bin/z3 -yices2path /home/mcc/BenchKit//yices/bin/yices -its -ltsminpath /home/mcc/BenchKit//lts_install_dir/ -smt -vmargs -Dosgi.locking=none -Declipse.stateSaveDelayInterval=-1 -Dosgi.configuration.area=/tmp/.eclipse -Xss8m -Xms40m -Xmx8192m -Dfile.encoding=UTF-8 -Dosgi.requiredJavaVersion=1.6
Mar 16, 2019 12:26:42 PM fr.lip6.move.gal.application.Application start
INFO: Running its-tools with arguments : [-pnfolder, /home/mcc/execution, -examination, LTLFireability, -z3path, /home/mcc/BenchKit//z3/bin/z3, -yices2path, /home/mcc/BenchKit//yices/bin/yices, -its, -ltsminpath, /home/mcc/BenchKit//lts_install_dir/, -smt]
Mar 16, 2019 12:26:42 PM fr.lip6.move.gal.application.MccTranslator transformPNML
INFO: Parsing pnml file : /home/mcc/execution/model.pnml
Mar 16, 2019 12:26:42 PM fr.lip6.move.gal.nupn.PTNetReader loadFromXML
INFO: Load time of PNML (sax parser for PT used): 34 ms
Mar 16, 2019 12:26:42 PM fr.lip6.move.gal.pnml.togal.PTGALTransformer handlePage
INFO: Transformed 25 places.
Mar 16, 2019 12:26:42 PM fr.lip6.move.gal.pnml.togal.PTGALTransformer handlePage
INFO: Transformed 18 transitions.
Mar 16, 2019 12:26:42 PM fr.lip6.move.serialization.SerializationUtil systemToFile
INFO: Time to serialize gal into /home/mcc/execution/model.pnml.img.gal : 8 ms
Mar 16, 2019 12:26:43 PM fr.lip6.move.gal.instantiate.GALRewriter flatten
INFO: Flatten gal took : 30 ms
Mar 16, 2019 12:26:43 PM fr.lip6.move.serialization.SerializationUtil systemToFile
INFO: Time to serialize gal into /home/mcc/execution/LTLFireability.pnml.gal : 2 ms
Mar 16, 2019 12:26:43 PM fr.lip6.move.serialization.SerializationUtil serializePropertiesForITSLTLTools
INFO: Time to serialize properties into /home/mcc/execution/LTLFireability.ltl : 2 ms
Mar 16, 2019 12:26:43 PM fr.lip6.move.gal.semantics.DeterministicNextBuilder getDeterministicNext
INFO: Input system was already deterministic with 18 transitions.
Mar 16, 2019 12:26:43 PM fr.lip6.move.gal.gal2smt.bmc.KInductionSolver computeAndDeclareInvariants
INFO: Computed 8 place invariants in 11 ms
Mar 16, 2019 12:26:43 PM fr.lip6.move.gal.gal2smt.bmc.KInductionSolver init
INFO: Proved 25 variables to be positive in 113 ms
Mar 16, 2019 12:26:43 PM fr.lip6.move.gal.gal2smt.bmc.NecessaryEnablingsolver computeAblingMatrix
INFO: Computing symmetric may disable matrix : 18 transitions.
Mar 16, 2019 12:26:43 PM fr.lip6.move.gal.gal2smt.bmc.NecessaryEnablingsolver printStats
INFO: Computation of disable matrix completed :0/18 took 0 ms. Total solver calls (SAT/UNSAT): 0(0/0)
Mar 16, 2019 12:26:43 PM fr.lip6.move.gal.gal2smt.bmc.NecessaryEnablingsolver printStats
INFO: Computation of Complete disable matrix. took 1 ms. Total solver calls (SAT/UNSAT): 0(0/0)
Mar 16, 2019 12:26:43 PM fr.lip6.move.gal.gal2smt.bmc.NecessaryEnablingsolver computeAblingMatrix
INFO: Computing symmetric may enable matrix : 18 transitions.
Mar 16, 2019 12:26:43 PM fr.lip6.move.gal.gal2smt.bmc.NecessaryEnablingsolver printStats
INFO: Computation of Complete enable matrix. took 0 ms. Total solver calls (SAT/UNSAT): 0(0/0)
Mar 16, 2019 12:26:43 PM fr.lip6.move.gal.gal2smt.bmc.NecessaryEnablingsolver computeCoEnablingMatrix
INFO: Computing symmetric co enabling matrix : 18 transitions.
Mar 16, 2019 12:26:44 PM fr.lip6.move.gal.gal2smt.bmc.NecessaryEnablingsolver printStats
INFO: Computation of Finished co-enabling matrix. took 380 ms. Total solver calls (SAT/UNSAT): 111(111/0)
Mar 16, 2019 12:26:44 PM fr.lip6.move.gal.gal2smt.bmc.NecessaryEnablingsolver computeDoNotAccord
INFO: Computing Do-Not-Accords matrix : 18 transitions.
Mar 16, 2019 12:26:44 PM fr.lip6.move.gal.gal2smt.bmc.NecessaryEnablingsolver printStats
INFO: Computation of Completed DNA matrix. took 198 ms. Total solver calls (SAT/UNSAT): 33(0/33)
Mar 16, 2019 12:26:44 PM fr.lip6.move.gal.gal2pins.Gal2PinsTransformerNext transform
INFO: Built C files in 1330ms conformant to PINS in folder :/home/mcc/execution
pins2lts-mc, 0.000: Registering PINS so language module
pins2lts-mc( 0/ 8), 0.001: Loading model from ./gal.so
pins2lts-mc( 2/ 8), 0.001: library has no initializer
pins2lts-mc( 5/ 8), 0.000: library has no initializer
pins2lts-mc( 1/ 8), 0.001: library has no initializer
pins2lts-mc( 2/ 8), 0.001: loading model GAL
pins2lts-mc( 3/ 8), 0.001: library has no initializer
pins2lts-mc( 3/ 8), 0.001: loading model GAL
pins2lts-mc( 4/ 8), 0.000: library has no initializer
pins2lts-mc( 4/ 8), 0.015: loading model GAL
pins2lts-mc( 6/ 8), 0.000: library has no initializer
pins2lts-mc( 1/ 8), 0.001: loading model GAL
pins2lts-mc( 0/ 8), 0.001: library has no initializer
pins2lts-mc( 6/ 8), 0.015: loading model GAL
pins2lts-mc( 0/ 8), 0.016: loading model GAL
pins2lts-mc( 6/ 8), 0.015: completed loading model GAL
pins2lts-mc( 6/ 8), 0.015: LTL layer: formula: ((LTLAP1==true))U(X(X(<>((LTLAP2==true)))))
pins2lts-mc( 2/ 8), 0.015: completed loading model GAL
pins2lts-mc( 5/ 8), 0.000: loading model GAL
pins2lts-mc( 1/ 8), 0.016: completed loading model GAL
pins2lts-mc( 0/ 8), 0.016: completed loading model GAL
pins2lts-mc( 3/ 8), 0.015: completed loading model GAL
pins2lts-mc( 6/ 8), 0.015: "((LTLAP1==true))U(X(X(<>((LTLAP2==true)))))" is not a file, parsing as formula...
pins2lts-mc( 5/ 8), 0.015: completed loading model GAL
pins2lts-mc( 6/ 8), 0.015: Using Spin LTL semantics
pins2lts-mc( 7/ 8), 0.014: library has no initializer
pins2lts-mc( 7/ 8), 0.015: loading model GAL
pins2lts-mc( 4/ 8), 0.015: completed loading model GAL
pins2lts-mc( 7/ 8), 0.015: completed loading model GAL
pins2lts-mc( 0/ 8), 0.039: Weak Buchi automaton detected, adding non-accepting as progress label.
pins2lts-mc( 0/ 8), 0.195: DFS-FIFO for weak LTL, using special progress label 35
pins2lts-mc( 0/ 8), 0.195: There are 36 state labels and 1 edge labels
pins2lts-mc( 0/ 8), 0.195: State length is 26, there are 21 groups
pins2lts-mc( 0/ 8), 0.195: Running dfsfifo using 8 cores
pins2lts-mc( 0/ 8), 0.195: Using a tree table with 2^27 elements
pins2lts-mc( 0/ 8), 0.195: Successor permutation: rr
pins2lts-mc( 0/ 8), 0.195: Global bits: 2, count bits: 0, local bits: 0
pins2lts-mc( 6/ 8), 0.331: ~114 levels ~960 states ~6904 transitions
pins2lts-mc( 6/ 8), 0.477: ~224 levels ~1920 states ~15392 transitions
pins2lts-mc( 6/ 8), 0.711: ~448 levels ~3840 states ~34064 transitions
pins2lts-mc( 6/ 8), 1.155: ~886 levels ~7680 states ~72776 transitions
pins2lts-mc( 6/ 8), 1.899: ~1771 levels ~15360 states ~161928 transitions
pins2lts-mc( 6/ 8), 2.918: ~3538 levels ~30720 states ~337592 transitions
pins2lts-mc( 6/ 8), 4.183: ~7144 levels ~61440 states ~707376 transitions
pins2lts-mc( 6/ 8), 6.373: ~14284 levels ~122880 states ~1470304 transitions
pins2lts-mc( 6/ 8), 8.867: ~28427 levels ~245760 states ~2886496 transitions
pins2lts-mc( 6/ 8), 9.456: ~33801 levels ~491520 states ~3238936 transitions
pins2lts-mc( 6/ 8), 10.568: ~33810 levels ~983040 states ~4006984 transitions
pins2lts-mc( 6/ 8), 12.405: ~33837 levels ~1966080 states ~5664288 transitions
pins2lts-mc( 6/ 8), 14.848: ~33927 levels ~3932160 states ~8758624 transitions
pins2lts-mc( 6/ 8), 19.629: ~34035 levels ~7864320 states ~15550416 transitions
pins2lts-mc( 6/ 8), 28.460: ~34422 levels ~15728640 states ~28680592 transitions
pins2lts-mc( 6/ 8), 47.078: ~34755 levels ~31457280 states ~54362936 transitions
pins2lts-mc( 6/ 8), 88.791: ~35979 levels ~62914560 states ~105987840 transitions
pins2lts-mc( 6/ 8), 162.276: Error: tree leafs table full! Change -s/--ratio.
pins2lts-mc( 0/ 8), 162.282:
pins2lts-mc( 0/ 8), 162.282: mean standard work distribution: 264.6% (states) 264.6% (transitions)
pins2lts-mc( 0/ 8), 162.282:
pins2lts-mc( 0/ 8), 162.282: Explored 10364103 states 17353065 transitions, fanout: 1.674
pins2lts-mc( 0/ 8), 162.282: Total exploration time 162.080 sec (162.070 sec minimum, 162.076 sec on average)
pins2lts-mc( 0/ 8), 162.282: States per second: 63944, Transitions per second: 107065
pins2lts-mc( 0/ 8), 162.282:
pins2lts-mc( 0/ 8), 162.282: Progress states detected: 0
pins2lts-mc( 0/ 8), 162.282: Redundant explorations: -3.1980
pins2lts-mc( 0/ 8), 162.282:
pins2lts-mc( 0/ 8), 162.282: Queue width: 8B, total height: 36908, memory: 0.28MB
pins2lts-mc( 0/ 8), 162.282: Tree memory: 337.7MB, 33.1 B/state, compr.: 31.2%
pins2lts-mc( 0/ 8), 162.283: Tree fill ratio (roots/leafs): 7.0%/99.0%
pins2lts-mc( 0/ 8), 162.283: Stored 18 string chucks using 0MB
pins2lts-mc( 0/ 8), 162.283: Total memory used for chunk indexing: 0MB
pins2lts-mc( 0/ 8), 162.283: Est. total memory use: 338.0MB (~1024.3MB paged-in)
java.lang.RuntimeException: Unexpected exception when executing ltsmin :CommandLine [args=[/home/mcc/BenchKit//lts_install_dir//bin/pins2lts-mc, ./gal.so, --threads=8, --when, --ltl, ((LTLAP1==true))U(X(X(<>((LTLAP2==true))))), --buchi-type=spotba], workingDir=/home/mcc/execution]
255
at fr.lip6.move.gal.application.LTSminRunner.checkProperty(LTSminRunner.java:167)
at fr.lip6.move.gal.application.LTSminRunner.access$9(LTSminRunner.java:122)
at fr.lip6.move.gal.application.LTSminRunner$1.run(LTSminRunner.java:91)
at java.lang.Thread.run(Thread.java:748)

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="ClientsAndServers-PT-N1000P0"
export BK_EXAMINATION="LTLFireability"
export BK_TOOL="itstools"
export BK_RESULT_DIR="/tmp/BK_RESULTS/OUTPUTS"
export BK_TIME_CONFINEMENT="3600"
export BK_MEMORY_CONFINEMENT="16384"

# 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 2-3957"
echo " Executing tool itstools"
echo " Input is ClientsAndServers-PT-N1000P0, examination is LTLFireability"
echo " Time confinement is $BK_TIME_CONFINEMENT seconds"
echo " Memory confinement is 16384 MBytes"
echo " Number of cores is 4"
echo " Run identifier is r030-smll-155225127000385"
echo "====================================================================="
echo
echo "--------------------"
echo "preparation of the directory to be used:"

tar xzf /home/mcc/BenchKit/INPUTS/ClientsAndServers-PT-N1000P0.tgz
mv ClientsAndServers-PT-N1000P0 execution
cd execution
if [ "LTLFireability" = "GlobalProperties" ] ; then
rm -f GenericPropertiesVerdict.xml
fi
if [ "LTLFireability" = "UpperBounds" ] ; 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 [ "LTLFireability" = "UpperBounds" ] ; then
echo "The expected result is a vector of positive values"
echo NUM_VECTOR
elif [ "LTLFireability" != "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 "LTLFireability.txt" ] ; then
echo "here is the order used to build the result vector(from text file)"
for x in $(grep Property LTLFireability.txt | cut -d ' ' -f 2 | sort -u) ; do
echo "FORMULA_NAME $x"
done
elif [ -f "LTLFireability.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 '' LTLFireability.xml | cut -d '>' -f 2 | cut -d '<' -f 1 | sort -u) ; do
echo "FORMULA_NAME $x"
done
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 ;