Execution Chart

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

Trace from the execution

Formatting '/data/fko/mcc2021-input.r159-oct2-162089268400475.qcow2', fmt=qcow2 size=4294967296 backing_file=/data/fko/mcc2021-input.qcow2 cluster_size=65536 lazy_refcounts=off refcount_bits=16
Waiting for the VM to be ready (probing ssh)
..................................................................................................................................
=====================================================================
Generated by BenchKit 2-4028
Executing tool itstools
Input is PolyORBNT-PT-S05J80, examination is UpperBounds
Time confinement is 3600 seconds
Memory confinement is 16384 MBytes
Number of cores is 4
Run identifier is r159-oct2-162089268400475
=====================================================================

--------------------
preparation of the directory to be used:
/home/mcc/execution
total 6.3M
-rw-r--r-- 1 mcc users 229K May 5 16:58 CTLCardinality.txt
-rw-r--r-- 1 mcc users 892K May 10 09:43 CTLCardinality.xml
-rw-r--r-- 1 mcc users 367K May 5 16:58 CTLFireability.txt
-rw-r--r-- 1 mcc users 1.6M May 10 09:43 CTLFireability.xml
-rw-r--r-- 1 mcc users 4.2K May 6 14:48 GenericPropertiesDefinition.xml
-rw-r--r-- 1 mcc users 27K Mar 28 16:28 LTLCardinality.txt
-rw-r--r-- 1 mcc users 81K Mar 28 16:28 LTLCardinality.xml
-rw-r--r-- 1 mcc users 56K Mar 28 16:28 LTLFireability.txt
-rw-r--r-- 1 mcc users 174K Mar 28 16:28 LTLFireability.xml
-rw-r--r-- 1 mcc users 27K Mar 27 09:32 ReachabilityCardinality.txt
-rw-r--r-- 1 mcc users 75K Mar 27 09:32 ReachabilityCardinality.xml
-rw-r--r-- 1 mcc users 28K Mar 25 12:21 ReachabilityFireability.txt
-rw-r--r-- 1 mcc users 93K Mar 25 12:21 ReachabilityFireability.xml
-rw-r--r-- 1 mcc users 1.8K Mar 22 08:13 UpperBounds.txt
-rw-r--r-- 1 mcc users 3.9K Mar 22 08:13 UpperBounds.xml
-rw-r--r-- 1 mcc users 5 May 5 16:51 equiv_col
-rw-r--r-- 1 mcc users 7 May 5 16:51 instance
-rw-r--r-- 1 mcc users 6 May 5 16:51 iscolored
-rw-r--r-- 1 mcc users 2.7M May 5 16:51 model.pnml

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

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

The expected result is a vector of positive values
NUM_VECTOR

here is the order used to build the result vector(from text file)
FORMULA_NAME PolyORBNT-PT-S05J80-UpperBounds-00
FORMULA_NAME PolyORBNT-PT-S05J80-UpperBounds-01
FORMULA_NAME PolyORBNT-PT-S05J80-UpperBounds-02
FORMULA_NAME PolyORBNT-PT-S05J80-UpperBounds-03
FORMULA_NAME PolyORBNT-PT-S05J80-UpperBounds-04
FORMULA_NAME PolyORBNT-PT-S05J80-UpperBounds-05
FORMULA_NAME PolyORBNT-PT-S05J80-UpperBounds-06
FORMULA_NAME PolyORBNT-PT-S05J80-UpperBounds-07
FORMULA_NAME PolyORBNT-PT-S05J80-UpperBounds-08
FORMULA_NAME PolyORBNT-PT-S05J80-UpperBounds-09
FORMULA_NAME PolyORBNT-PT-S05J80-UpperBounds-10
FORMULA_NAME PolyORBNT-PT-S05J80-UpperBounds-11
FORMULA_NAME PolyORBNT-PT-S05J80-UpperBounds-12
FORMULA_NAME PolyORBNT-PT-S05J80-UpperBounds-13
FORMULA_NAME PolyORBNT-PT-S05J80-UpperBounds-14
FORMULA_NAME PolyORBNT-PT-S05J80-UpperBounds-15

=== Now, execution of the tool begins

BK_START 1621224986813

Running Version 0
[2021-05-17 04:16:28] [INFO ] Running its-tools with arguments : [-pnfolder, /home/mcc/execution, -examination, UpperBounds, -spotpath, /home/mcc/BenchKit/bin//..//ltlfilt, -z3path, /home/mcc/BenchKit/bin//..//z3/bin/z3, -yices2path, /home/mcc/BenchKit/bin//..//yices/bin/yices, -its, -ltsmin, -greatspnpath, /home/mcc/BenchKit/bin//..//greatspn/, -order, META, -manyOrder, -smt, -timeout, 3600]
[2021-05-17 04:16:28] [INFO ] Parsing pnml file : /home/mcc/execution/model.pnml
[2021-05-17 04:16:28] [INFO ] Load time of PNML (sax parser for PT used): 205 ms
[2021-05-17 04:16:28] [INFO ] Transformed 1189 places.
[2021-05-17 04:16:28] [INFO ] Transformed 2350 transitions.
[2021-05-17 04:16:28] [INFO ] Parsed PT model containing 1189 places and 2350 transitions in 255 ms.
Parsed 16 properties from file /home/mcc/execution/UpperBounds.xml in 6 ms.
Ensure Unique test removed 655 transitions
Reduce redundant transitions removed 655 transitions.
Normalized transition count is 1691 out of 1695 initially.
// Phase 1: matrix 1691 rows 1189 cols
[2021-05-17 04:16:28] [INFO ] Computed 182 place invariants in 183 ms
FORMULA PolyORBNT-PT-S05J80-UpperBounds-09 1 TECHNIQUES TOPOLOGICAL INITIAL_STATE
FORMULA PolyORBNT-PT-S05J80-UpperBounds-04 1 TECHNIQUES TOPOLOGICAL INITIAL_STATE
Incomplete random walk after 10000 steps, including 693 resets, run finished after 75 ms. (steps per millisecond=133 ) properties (out of 14) seen :26
FORMULA PolyORBNT-PT-S05J80-UpperBounds-14 1 TECHNIQUES TOPOLOGICAL RANDOM_WALK
FORMULA PolyORBNT-PT-S05J80-UpperBounds-12 1 TECHNIQUES TOPOLOGICAL RANDOM_WALK
FORMULA PolyORBNT-PT-S05J80-UpperBounds-06 3 TECHNIQUES TOPOLOGICAL RANDOM_WALK
FORMULA PolyORBNT-PT-S05J80-UpperBounds-05 1 TECHNIQUES TOPOLOGICAL RANDOM_WALK
FORMULA PolyORBNT-PT-S05J80-UpperBounds-03 3 TECHNIQUES TOPOLOGICAL RANDOM_WALK
Incomplete Best-First random walk after 10001 steps, including 102 resets, run finished after 23 ms. (steps per millisecond=434 ) properties (out of 9) seen :19
FORMULA PolyORBNT-PT-S05J80-UpperBounds-15 1 TECHNIQUES TOPOLOGICAL BESTFIRST_WALK
FORMULA PolyORBNT-PT-S05J80-UpperBounds-08 1 TECHNIQUES TOPOLOGICAL BESTFIRST_WALK
Incomplete Best-First random walk after 10001 steps, including 40 resets, run finished after 25 ms. (steps per millisecond=400 ) properties (out of 7) seen :17
Incomplete Best-First random walk after 10001 steps, including 40 resets, run finished after 26 ms. (steps per millisecond=384 ) properties (out of 7) seen :18
FORMULA PolyORBNT-PT-S05J80-UpperBounds-11 1 TECHNIQUES TOPOLOGICAL BESTFIRST_WALK
Incomplete Best-First random walk after 10001 steps, including 106 resets, run finished after 22 ms. (steps per millisecond=454 ) properties (out of 6) seen :17
Incomplete Best-First random walk after 10001 steps, including 102 resets, run finished after 23 ms. (steps per millisecond=434 ) properties (out of 6) seen :17
Incomplete Best-First random walk after 10000 steps, including 76 resets, run finished after 23 ms. (steps per millisecond=434 ) properties (out of 6) seen :17
[2021-05-17 04:16:29] [INFO ] Flow matrix only has 1691 transitions (discarded 4 similar events)
// Phase 1: matrix 1691 rows 1189 cols
[2021-05-17 04:16:29] [INFO ] Computed 182 place invariants in 131 ms
[2021-05-17 04:16:29] [INFO ] [Real]Absence check using 157 positive place invariants in 42 ms returned sat
[2021-05-17 04:16:29] [INFO ] [Real]Absence check using 157 positive and 25 generalized place invariants in 31 ms returned unsat
[2021-05-17 04:16:29] [INFO ] [Real]Absence check using 157 positive place invariants in 66 ms returned sat
[2021-05-17 04:16:29] [INFO ] [Real]Absence check using 157 positive and 25 generalized place invariants in 57 ms returned sat
[2021-05-17 04:16:29] [INFO ] [Real]Adding state equation constraints to refine reachable states.
[2021-05-17 04:16:30] [INFO ] [Real]Absence check using state equation in 484 ms returned unsat
[2021-05-17 04:16:30] [INFO ] [Real]Absence check using 157 positive place invariants in 32 ms returned sat
[2021-05-17 04:16:30] [INFO ] [Real]Absence check using 157 positive and 25 generalized place invariants in 35 ms returned unsat
[2021-05-17 04:16:30] [INFO ] [Real]Absence check using 157 positive place invariants in 32 ms returned sat
[2021-05-17 04:16:30] [INFO ] [Real]Absence check using 157 positive and 25 generalized place invariants in 32 ms returned sat
[2021-05-17 04:16:30] [INFO ] [Real]Adding state equation constraints to refine reachable states.
[2021-05-17 04:16:31] [INFO ] [Real]Absence check using state equation in 613 ms returned sat
[2021-05-17 04:16:31] [INFO ] Solution in real domain found non-integer solution.
[2021-05-17 04:16:31] [INFO ] [Nat]Absence check using 157 positive place invariants in 38 ms returned sat
[2021-05-17 04:16:31] [INFO ] [Nat]Absence check using 157 positive and 25 generalized place invariants in 33 ms returned sat
[2021-05-17 04:16:31] [INFO ] [Nat]Adding state equation constraints to refine reachable states.
[2021-05-17 04:16:32] [INFO ] [Nat]Absence check using state equation in 836 ms returned sat
[2021-05-17 04:16:32] [INFO ] State equation strengthened by 1 read => feed constraints.
[2021-05-17 04:16:32] [INFO ] [Nat]Added 1 Read/Feed constraints in 432 ms returned sat
[2021-05-17 04:16:33] [INFO ] Computed and/alt/rep : 949/2209/949 causal constraints (skipped 736 transitions) in 141 ms.
[2021-05-17 04:16:34] [INFO ] Deduced a trap composed of 424 places in 485 ms of which 4 ms to minimize.
[2021-05-17 04:16:34] [INFO ] Trap strengthening (SAT) tested/added 2/1 trap constraints in 861 ms
[2021-05-17 04:16:34] [INFO ] Added : 13 causal constraints over 4 iterations in 1514 ms. Result :sat
Minimization took 1557 ms.
[2021-05-17 04:16:36] [INFO ] [Real]Absence check using 157 positive place invariants in 34 ms returned sat
[2021-05-17 04:16:36] [INFO ] [Real]Absence check using 157 positive and 25 generalized place invariants in 12 ms returned unsat
[2021-05-17 04:16:36] [INFO ] [Real]Absence check using 157 positive place invariants in 29 ms returned sat
[2021-05-17 04:16:36] [INFO ] [Real]Absence check using 157 positive and 25 generalized place invariants in 49 ms returned sat
[2021-05-17 04:16:36] [INFO ] [Real]Adding state equation constraints to refine reachable states.
[2021-05-17 04:16:38] [INFO ] [Real]Absence check using state equation in 2151 ms returned sat
[2021-05-17 04:16:39] [INFO ] Solution in real domain found non-integer solution.
[2021-05-17 04:16:39] [INFO ] [Nat]Absence check using 157 positive place invariants in 33 ms returned sat
[2021-05-17 04:16:39] [INFO ] [Nat]Absence check using 157 positive and 25 generalized place invariants in 32 ms returned sat
[2021-05-17 04:16:39] [INFO ] [Nat]Adding state equation constraints to refine reachable states.
[2021-05-17 04:16:39] [INFO ] [Nat]Absence check using state equation in 572 ms returned sat
[2021-05-17 04:16:39] [INFO ] [Nat]Added 1 Read/Feed constraints in 0 ms returned sat
[2021-05-17 04:16:40] [INFO ] Deduced a trap composed of 24 places in 884 ms of which 4 ms to minimize.
[2021-05-17 04:16:40] [INFO ] Trap strengthening (SAT) tested/added 2/1 trap constraints in 995 ms
[2021-05-17 04:16:41] [INFO ] Computed and/alt/rep : 949/2209/949 causal constraints (skipped 736 transitions) in 86 ms.
[2021-05-17 04:16:44] [INFO ] Added : 25 causal constraints over 5 iterations in 3153 ms. Result :unknown
Current structural bounds on expressions (after SMT) : [1, 10, 5, 2, 1, 1] Max seen :[1, 10, 5, 0, 1, 0]
FORMULA PolyORBNT-PT-S05J80-UpperBounds-10 1 TECHNIQUES TOPOLOGICAL SAT_SMT RANDOM_WALK
FORMULA PolyORBNT-PT-S05J80-UpperBounds-02 5 TECHNIQUES TOPOLOGICAL SAT_SMT RANDOM_WALK
FORMULA PolyORBNT-PT-S05J80-UpperBounds-01 10 TECHNIQUES TOPOLOGICAL SAT_SMT RANDOM_WALK
FORMULA PolyORBNT-PT-S05J80-UpperBounds-00 1 TECHNIQUES TOPOLOGICAL SAT_SMT RANDOM_WALK
Incomplete Parikh walk after 13600 steps, including 1095 resets, run finished after 99 ms. (steps per millisecond=137 ) properties (out of 2) seen :2 could not realise parikh vector
FORMULA PolyORBNT-PT-S05J80-UpperBounds-07 2 TECHNIQUES TOPOLOGICAL PARIKH_WALK
Incomplete Parikh walk after 2700 steps, including 187 resets, run finished after 14 ms. (steps per millisecond=192 ) properties (out of 1) seen :0 could not realise parikh vector
Support contains 1 out of 1189 places. Attempting structural reductions.
Starting structural reductions, iteration 0 : 1189/1189 places, 1695/1695 transitions.
Ensure Unique test removed 5 places
Drop transitions removed 86 transitions
Trivial Post-agglo rules discarded 86 transitions
Performed 86 trivial Post agglomeration. Transition count delta: 86
Iterating post reduction 0 with 91 rules applied. Total rules applied 91 place count 1184 transition count 1609
Reduce places removed 86 places and 0 transitions.
Iterating post reduction 1 with 86 rules applied. Total rules applied 177 place count 1098 transition count 1609
Performed 85 Pre agglomeration using Quasi-Persistent + Divergent Free condition..
Pre-agglomeration after 2 with 85 Pre rules applied. Total rules applied 177 place count 1098 transition count 1524
Deduced a syphon composed of 85 places in 2 ms
Reduce places removed 85 places and 0 transitions.
Iterating global reduction 2 with 170 rules applied. Total rules applied 347 place count 1013 transition count 1524
Discarding 1 places :
Symmetric choice reduction at 2 with 1 rule applications. Total rules 348 place count 1012 transition count 1523
Iterating global reduction 2 with 1 rules applied. Total rules applied 349 place count 1012 transition count 1523
Performed 2 Post agglomeration using F-continuation condition.Transition count delta: 2
Deduced a syphon composed of 2 places in 1 ms
Reduce places removed 2 places and 0 transitions.
Iterating global reduction 2 with 4 rules applied. Total rules applied 353 place count 1010 transition count 1521
Applied a total of 353 rules in 357 ms. Remains 1010 /1189 variables (removed 179) and now considering 1521/1695 (removed 174) transitions.
[2021-05-17 04:16:44] [INFO ] Flow matrix only has 1517 transitions (discarded 4 similar events)
// Phase 1: matrix 1517 rows 1010 cols
[2021-05-17 04:16:44] [INFO ] Computed 177 place invariants in 44 ms
[2021-05-17 04:16:46] [INFO ] Dead Transitions using invariants and state equation in 2215 ms returned [987, 988, 989, 990, 991, 992, 994, 995, 996, 997, 998, 1001, 1002, 1004, 1005, 1009, 1010, 1011, 1012, 1013, 1015, 1016, 1018, 1019, 1020, 1021, 1022, 1023, 1025, 1026, 1028, 1029, 1030, 1032, 1033, 1034, 1035, 1036, 1037, 1038, 1039, 1040, 1041, 1042, 1045, 1047, 1048, 1049, 1050, 1051, 1052, 1053, 1055, 1056, 1057, 1058, 1060, 1062, 1063, 1064, 1065, 1067, 1068, 1069, 1070, 1071, 1074, 1075, 1077, 1078, 1079, 1080, 1081, 1082, 1083, 1084, 1085, 1086, 1088, 1091, 1093, 1094, 1095, 1096, 1097, 1098, 1099, 1100, 1101, 1102, 1104, 1105, 1109, 1110, 1111]
Found 95 dead transitions using SMT.
Drop transitions removed 95 transitions
Dead transitions reduction (with SMT) triggered by suspicious arc values removed 95 transitions :[1111, 1110, 1109, 1105, 1104, 1102, 1101, 1100, 1099, 1098, 1097, 1096, 1095, 1094, 1093, 1091, 1088, 1086, 1085, 1084, 1083, 1082, 1081, 1080, 1079, 1078, 1077, 1075, 1074, 1071, 1070, 1069, 1068, 1067, 1065, 1064, 1063, 1062, 1060, 1058, 1057, 1056, 1055, 1053, 1052, 1051, 1050, 1049, 1048, 1047, 1045, 1042, 1041, 1040, 1039, 1038, 1037, 1036, 1035, 1034, 1033, 1032, 1030, 1029, 1028, 1026, 1025, 1023, 1022, 1021, 1020, 1019, 1018, 1016, 1015, 1013, 1012, 1011, 1010, 1009, 1005, 1004, 1002, 1001, 998, 997, 996, 995, 994, 992, 991, 990, 989, 988, 987]
Starting structural reductions, iteration 1 : 1010/1189 places, 1426/1695 transitions.
Applied a total of 0 rules in 105 ms. Remains 1010 /1010 variables (removed 0) and now considering 1426/1426 (removed 0) transitions.
Finished structural reductions, in 2 iterations. Remains : 1010/1189 places, 1426/1695 transitions.
Normalized transition count is 1422 out of 1426 initially.
// Phase 1: matrix 1422 rows 1010 cols
[2021-05-17 04:16:47] [INFO ] Computed 177 place invariants in 96 ms
Incomplete random walk after 1000000 steps, including 51782 resets, run finished after 7683 ms. (steps per millisecond=130 ) properties (out of 1) seen :1
FORMULA PolyORBNT-PT-S05J80-UpperBounds-13 1 TECHNIQUES TOPOLOGICAL RANDOM_WALK
All properties solved without resorting to model-checking.

BK_STOP 1621225014852

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

+ export BINDIR=/home/mcc/BenchKit/bin//../
+ BINDIR=/home/mcc/BenchKit/bin//../
++ pwd
+ export MODEL=/home/mcc/execution
+ MODEL=/home/mcc/execution
+ [[ UpperBounds = StateSpace ]]
+ /home/mcc/BenchKit/bin//..//runeclipse.sh /home/mcc/execution UpperBounds -its -ltsmin -greatspnpath /home/mcc/BenchKit/bin//..//greatspn/ -order META -manyOrder -smt -timeout 3600
+ ulimit -s 65536
+ [[ -z '' ]]
+ export LTSMIN_MEM_SIZE=8589934592
+ LTSMIN_MEM_SIZE=8589934592
++ cut -d . -f 9
++ ls /home/mcc/BenchKit/bin//..//itstools/plugins/fr.lip6.move.gal.application.pnmcc_1.0.0.202104292328.jar
+ VERSION=0
+ echo 'Running Version 0'
+ /home/mcc/BenchKit/bin//..//itstools/its-tools -data /home/mcc/execution/workspace -pnfolder /home/mcc/execution -examination UpperBounds -spotpath /home/mcc/BenchKit/bin//..//ltlfilt -z3path /home/mcc/BenchKit/bin//..//z3/bin/z3 -yices2path /home/mcc/BenchKit/bin//..//yices/bin/yices -its -ltsmin -greatspnpath /home/mcc/BenchKit/bin//..//greatspn/ -order META -manyOrder -smt -timeout 3600 -vmargs -Dosgi.locking=none -Declipse.stateSaveDelayInterval=-1 -Dosgi.configuration.area=/tmp/.eclipse -Xss128m -Xms40m -Xmx16000m

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="PolyORBNT-PT-S05J80"
export BK_EXAMINATION="UpperBounds"
export BK_TOOL="itstools"
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 2-4028"
echo " Executing tool itstools"
echo " Input is PolyORBNT-PT-S05J80, examination is UpperBounds"
echo " Time confinement is $BK_TIME_CONFINEMENT seconds"
echo " Memory confinement is 16384 MBytes"
echo " Number of cores is 4"
echo " Run identifier is r159-oct2-162089268400475"
echo "====================================================================="
echo
echo "--------------------"
echo "preparation of the directory to be used:"

tar xzf /home/mcc/BenchKit/INPUTS/PolyORBNT-PT-S05J80.tgz
mv PolyORBNT-PT-S05J80 execution
cd execution
if [ "UpperBounds" = "ReachabilityDeadlock" ] || [ "UpperBounds" = "UpperBounds" ] || [ "UpperBounds" = "QuasiLiveness" ] || [ "UpperBounds" = "StableMarking" ] || [ "UpperBounds" = "Liveness" ] || [ "UpperBounds" = "OneSafe" ] || [ "UpperBounds" = "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 [ "UpperBounds" = "UpperBounds" ] ; then
echo "The expected result is a vector of positive values"
echo NUM_VECTOR
elif [ "UpperBounds" != "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 "UpperBounds.txt" ] ; then
echo "here is the order used to build the result vector(from text file)"
for x in $(grep Property UpperBounds.txt | cut -d ' ' -f 2 | sort -u) ; do
echo "FORMULA_NAME $x"
done
elif [ -f "UpperBounds.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 '' UpperBounds.xml | cut -d '>' -f 2 | cut -d '<' -f 1 | sort -u) ; do
echo "FORMULA_NAME $x"
done
elif [ "UpperBounds" = "ReachabilityDeadlock" ] || [ "UpperBounds" = "QuasiLiveness" ] || [ "UpperBounds" = "StableMarking" ] || [ "UpperBounds" = "Liveness" ] || [ "UpperBounds" = "OneSafe" ] ; then
echo "FORMULA_NAME UpperBounds"
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 ;