fond
Model Checking Contest 2023
13th edition, Paris, France, April 26, 2023 (at TOOLympics II)
Execution of r441-tajo-167905987000207
Last Updated
May 14, 2023

About the Execution of Smart+red for ShieldRVt-PT-050B

Execution Summary
Max Memory
Used (MB)
Time wait (ms) CPU Usage (ms) I/O Wait (ms) Computed Result Execution
Status
1443.987 164407.00 283989.00 113.50 T normal

Execution Chart

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

Trace from the execution

Formatting '/mnt/tpsp/fkordon/mcc2023-input.r441-tajo-167905987000207.qcow2', fmt=qcow2 size=4294967296 backing_file='/mnt/tpsp/fkordon/mcc2023-input.qcow2' encryption=off cluster_size=65536 lazy_refcounts=off
Waiting for the VM to be ready (probing ssh)
......................................................................................................................................................................................................................................................................
=====================================================================
Generated by BenchKit 2-5348
Executing tool smartxred
Input is ShieldRVt-PT-050B, examination is QuasiLiveness
Time confinement is 1800 seconds
Memory confinement is 16384 MBytes
Number of cores is 4
Run identifier is r441-tajo-167905987000207
=====================================================================

--------------------
preparation of the directory to be used:
/home/mcc/execution
total 1.1M
-rw-r--r-- 1 mcc users 6.8K Feb 25 22:53 CTLCardinality.txt
-rw-r--r-- 1 mcc users 76K Feb 25 22:53 CTLCardinality.xml
-rw-r--r-- 1 mcc users 5.6K Feb 25 22:52 CTLFireability.txt
-rw-r--r-- 1 mcc users 51K Feb 25 22:52 CTLFireability.xml
-rw-r--r-- 1 mcc users 4.2K Jan 29 11:41 GenericPropertiesDefinition.xml
-rw-r--r-- 1 mcc users 3.7K Feb 25 17:04 LTLCardinality.txt
-rw-r--r-- 1 mcc users 25K Feb 25 17:04 LTLCardinality.xml
-rw-r--r-- 1 mcc users 2.2K Feb 25 17:05 LTLFireability.txt
-rw-r--r-- 1 mcc users 16K Feb 25 17:05 LTLFireability.xml
-rw-r--r-- 1 mcc users 11K Feb 25 22:53 ReachabilityCardinality.txt
-rw-r--r-- 1 mcc users 116K Feb 25 22:53 ReachabilityCardinality.xml
-rw-r--r-- 1 mcc users 11K Feb 25 22:53 ReachabilityFireability.txt
-rw-r--r-- 1 mcc users 90K Feb 25 22:53 ReachabilityFireability.xml
-rw-r--r-- 1 mcc users 1.6K Feb 25 17:05 UpperBounds.txt
-rw-r--r-- 1 mcc users 3.7K Feb 25 17:05 UpperBounds.xml
-rw-r--r-- 1 mcc users 6 Mar 5 18:23 equiv_col
-rw-r--r-- 1 mcc users 5 Mar 5 18:23 instance
-rw-r--r-- 1 mcc users 6 Mar 5 18:23 iscolored
-rw-r--r-- 1 mcc users 614K 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

FORMULA_NAME QuasiLiveness

=== Now, execution of the tool begins

BK_START 1679557902698

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=QuasiLiveness
BK_BIN_PATH=/home/mcc/BenchKit/bin/
BK_TIME_CONFINEMENT=1800
BK_INPUT=ShieldRVt-PT-050B
Applying reductions before tool smart
Invoking reducer
Running Version 202303021504
[2023-03-23 07:51:45] [INFO ] Running its-tools with arguments : [-pnfolder, /home/mcc/execution, -examination, QuasiLiveness, -timeout, 180, -rebuildPNML]
[2023-03-23 07:51:45] [INFO ] Parsing pnml file : /home/mcc/execution/model.pnml
[2023-03-23 07:51:45] [INFO ] Load time of PNML (sax parser for PT used): 196 ms
[2023-03-23 07:51:45] [INFO ] Transformed 2503 places.
[2023-03-23 07:51:45] [INFO ] Transformed 2503 transitions.
[2023-03-23 07:51:45] [INFO ] Found NUPN structural information;
[2023-03-23 07:51:45] [INFO ] Parsed PT model containing 2503 places and 2503 transitions and 5906 arcs in 398 ms.
Starting structural reductions in LIVENESS mode, iteration 0 : 2503/2503 places, 2503/2503 transitions.
Drop transitions removed 802 transitions
Trivial Post-agglo rules discarded 802 transitions
Performed 802 trivial Post agglomeration. Transition count delta: 802
Iterating post reduction 0 with 802 rules applied. Total rules applied 802 place count 2503 transition count 1701
Reduce places removed 802 places and 0 transitions.
Ensure Unique test removed 1 transitions
Reduce isomorphic transitions removed 1 transitions.
Drop transitions removed 1 transitions
Trivial Post-agglo rules discarded 1 transitions
Performed 1 trivial Post agglomeration. Transition count delta: 1
Iterating post reduction 1 with 804 rules applied. Total rules applied 1606 place count 1701 transition count 1699
Reduce places removed 1 places and 0 transitions.
Iterating post reduction 2 with 1 rules applied. Total rules applied 1607 place count 1700 transition count 1699
Performed 200 Pre agglomeration using Quasi-Persistent + Divergent Free condition..
Pre-agglomeration after 3 with 200 Pre rules applied. Total rules applied 1607 place count 1700 transition count 1499
Deduced a syphon composed of 200 places in 17 ms
Reduce places removed 200 places and 0 transitions.
Iterating global reduction 3 with 400 rules applied. Total rules applied 2007 place count 1500 transition count 1499
Performed 949 Post agglomeration using F-continuation condition.Transition count delta: 949
Deduced a syphon composed of 949 places in 2 ms
Reduce places removed 949 places and 0 transitions.
Iterating global reduction 3 with 1898 rules applied. Total rules applied 3905 place count 551 transition count 550
Renaming transitions due to excessive name length > 1024 char.
Performed 101 Post agglomeration using F-continuation condition.Transition count delta: -100
Deduced a syphon composed of 101 places in 2 ms
Reduce places removed 101 places and 0 transitions.
Iterating global reduction 3 with 202 rules applied. Total rules applied 4107 place count 450 transition count 650
Performed 48 Post agglomeration using F-continuation condition.Transition count delta: -48
Deduced a syphon composed of 48 places in 1 ms
Reduce places removed 48 places and 0 transitions.
Iterating global reduction 3 with 96 rules applied. Total rules applied 4203 place count 402 transition count 698
Applied a total of 4203 rules in 395 ms. Remains 402 /2503 variables (removed 2101) and now considering 698/2503 (removed 1805) transitions.
// Phase 1: matrix 698 rows 402 cols
[2023-03-23 07:51:45] [INFO ] Computed 201 place invariants in 14 ms
[2023-03-23 07:51:46] [INFO ] Implicit Places using invariants in 687 ms returned [395]
Discarding 1 places :
Implicit Place search using SMT only with invariants took 714 ms to find 1 implicit places.
Starting structural reductions in LIVENESS mode, iteration 1 : 401/2503 places, 698/2503 transitions.
Applied a total of 0 rules in 10 ms. Remains 401 /401 variables (removed 0) and now considering 698/698 (removed 0) transitions.
Finished structural reductions in LIVENESS mode , in 2 iterations and 1119 ms. Remains : 401/2503 places, 698/2503 transitions.
Discarding 496 transitions out of 698. Remains 202
Initial state reduction rules removed 1 formulas.
Incomplete random walk after 10000 steps, including 2 resets, run finished after 730 ms. (steps per millisecond=13 ) properties (out of 201) seen :56
Incomplete Best-First random walk after 101 steps, including 2 resets, run finished after 3 ms. (steps per millisecond=33 ) properties (out of 145) seen :0
Incomplete Best-First random walk after 101 steps, including 2 resets, run finished after 3 ms. (steps per millisecond=33 ) properties (out of 145) seen :0
Incomplete Best-First random walk after 101 steps, including 2 resets, run finished after 2 ms. (steps per millisecond=50 ) properties (out of 145) seen :0
Incomplete Best-First random walk after 101 steps, including 2 resets, run finished after 2 ms. (steps per millisecond=50 ) properties (out of 145) seen :0
Incomplete Best-First random walk after 101 steps, including 2 resets, run finished after 3 ms. (steps per millisecond=33 ) properties (out of 145) seen :0
Incomplete Best-First random walk after 101 steps, including 2 resets, run finished after 4 ms. (steps per millisecond=25 ) properties (out of 145) seen :0
Incomplete Best-First random walk after 101 steps, including 2 resets, run finished after 5 ms. (steps per millisecond=20 ) properties (out of 145) seen :0
Incomplete Best-First random walk after 101 steps, including 2 resets, run finished after 5 ms. (steps per millisecond=20 ) properties (out of 145) seen :0
Incomplete Best-First random walk after 101 steps, including 2 resets, run finished after 4 ms. (steps per millisecond=25 ) properties (out of 145) seen :0
Incomplete Best-First random walk after 101 steps, including 2 resets, run finished after 4 ms. (steps per millisecond=25 ) properties (out of 145) seen :0
Incomplete Best-First random walk after 101 steps, including 2 resets, run finished after 4 ms. (steps per millisecond=25 ) properties (out of 145) seen :0
Incomplete Best-First random walk after 101 steps, including 2 resets, run finished after 5 ms. (steps per millisecond=20 ) properties (out of 145) seen :0
Incomplete Best-First random walk after 101 steps, including 2 resets, run finished after 5 ms. (steps per millisecond=20 ) properties (out of 145) seen :0
Incomplete Best-First random walk after 101 steps, including 2 resets, run finished after 4 ms. (steps per millisecond=25 ) properties (out of 145) seen :0
Incomplete Best-First random walk after 101 steps, including 2 resets, run finished after 3 ms. (steps per millisecond=33 ) properties (out of 145) seen :0
Incomplete Best-First random walk after 101 steps, including 2 resets, run finished after 3 ms. (steps per millisecond=33 ) properties (out of 145) seen :0
Incomplete Best-First random walk after 101 steps, including 2 resets, run finished after 4 ms. (steps per millisecond=25 ) properties (out of 145) seen :0
Incomplete Best-First random walk after 101 steps, including 2 resets, run finished after 5 ms. (steps per millisecond=20 ) properties (out of 145) seen :0
Incomplete Best-First random walk after 101 steps, including 2 resets, run finished after 4 ms. (steps per millisecond=25 ) properties (out of 145) seen :0
Incomplete Best-First random walk after 101 steps, including 2 resets, run finished after 5 ms. (steps per millisecond=20 ) properties (out of 145) seen :0
Incomplete Best-First random walk after 101 steps, including 2 resets, run finished after 4 ms. (steps per millisecond=25 ) properties (out of 145) seen :0
Incomplete Best-First random walk after 101 steps, including 2 resets, run finished after 4 ms. (steps per millisecond=25 ) properties (out of 145) seen :0
Incomplete Best-First random walk after 101 steps, including 2 resets, run finished after 5 ms. (steps per millisecond=20 ) properties (out of 145) seen :0
Incomplete Best-First random walk after 101 steps, including 2 resets, run finished after 4 ms. (steps per millisecond=25 ) properties (out of 145) seen :0
Incomplete Best-First random walk after 101 steps, including 2 resets, run finished after 4 ms. (steps per millisecond=25 ) properties (out of 145) seen :0
Incomplete Best-First random walk after 101 steps, including 2 resets, run finished after 4 ms. (steps per millisecond=25 ) properties (out of 145) seen :0
Incomplete Best-First random walk after 101 steps, including 2 resets, run finished after 5 ms. (steps per millisecond=20 ) properties (out of 145) seen :0
Incomplete Best-First random walk after 101 steps, including 2 resets, run finished after 4 ms. (steps per millisecond=25 ) properties (out of 145) seen :0
Incomplete Best-First random walk after 101 steps, including 2 resets, run finished after 4 ms. (steps per millisecond=25 ) properties (out of 145) seen :0
Incomplete Best-First random walk after 101 steps, including 2 resets, run finished after 3 ms. (steps per millisecond=33 ) properties (out of 145) seen :0
Incomplete Best-First random walk after 100 steps, including 2 resets, run finished after 4 ms. (steps per millisecond=25 ) properties (out of 145) seen :0
Incomplete Best-First random walk after 101 steps, including 2 resets, run finished after 3 ms. (steps per millisecond=33 ) properties (out of 145) seen :0
Incomplete Best-First random walk after 101 steps, including 2 resets, run finished after 3 ms. (steps per millisecond=33 ) properties (out of 145) seen :0
Incomplete Best-First random walk after 100 steps, including 2 resets, run finished after 4 ms. (steps per millisecond=25 ) properties (out of 145) seen :0
Incomplete Best-First random walk after 101 steps, including 2 resets, run finished after 4 ms. (steps per millisecond=25 ) properties (out of 145) seen :0
Incomplete Best-First random walk after 101 steps, including 2 resets, run finished after 2 ms. (steps per millisecond=50 ) properties (out of 145) seen :0
Incomplete Best-First random walk after 101 steps, including 2 resets, run finished after 3 ms. (steps per millisecond=33 ) properties (out of 145) seen :0
Incomplete Best-First random walk after 100 steps, including 2 resets, run finished after 2 ms. (steps per millisecond=50 ) properties (out of 145) seen :0
Incomplete Best-First random walk after 101 steps, including 2 resets, run finished after 3 ms. (steps per millisecond=33 ) properties (out of 145) seen :0
Incomplete Best-First random walk after 100 steps, including 2 resets, run finished after 3 ms. (steps per millisecond=33 ) properties (out of 145) seen :0
Incomplete Best-First random walk after 101 steps, including 2 resets, run finished after 2 ms. (steps per millisecond=50 ) properties (out of 145) seen :0
Incomplete Best-First random walk after 100 steps, including 2 resets, run finished after 2 ms. (steps per millisecond=50 ) properties (out of 145) seen :0
Incomplete Best-First random walk after 101 steps, including 2 resets, run finished after 3 ms. (steps per millisecond=33 ) properties (out of 145) seen :0
Incomplete Best-First random walk after 101 steps, including 2 resets, run finished after 3 ms. (steps per millisecond=33 ) properties (out of 145) seen :0
Incomplete Best-First random walk after 101 steps, including 2 resets, run finished after 5 ms. (steps per millisecond=20 ) properties (out of 145) seen :0
Incomplete Best-First random walk after 101 steps, including 2 resets, run finished after 5 ms. (steps per millisecond=20 ) properties (out of 145) seen :0
Incomplete Best-First random walk after 101 steps, including 2 resets, run finished after 4 ms. (steps per millisecond=25 ) properties (out of 145) seen :0
Incomplete Best-First random walk after 101 steps, including 2 resets, run finished after 6 ms. (steps per millisecond=16 ) properties (out of 145) seen :0
Incomplete Best-First random walk after 101 steps, including 2 resets, run finished after 4 ms. (steps per millisecond=25 ) properties (out of 145) seen :0
Incomplete Best-First random walk after 100 steps, including 2 resets, run finished after 4 ms. (steps per millisecond=25 ) properties (out of 145) seen :0
Running SMT prover for 145 properties.
// Phase 1: matrix 698 rows 401 cols
[2023-03-23 07:51:47] [INFO ] Computed 200 place invariants in 10 ms
[2023-03-23 07:51:48] [INFO ] [Real]Absence check using 200 positive place invariants in 34 ms returned sat
[2023-03-23 07:51:55] [INFO ] After 7357ms SMT Verify possible using all constraints in real domain returned unsat :0 sat :0 real:145
[2023-03-23 07:51:55] [INFO ] [Nat]Absence check using 200 positive place invariants in 26 ms returned sat
[2023-03-23 07:52:00] [INFO ] After 3637ms SMT Verify possible using state equation in natural domain returned unsat :0 sat :145
[2023-03-23 07:52:00] [INFO ] State equation strengthened by 496 read => feed constraints.
[2023-03-23 07:52:20] [INFO ] After 19905ms SMT Verify possible using 496 Read/Feed constraints in natural domain returned unsat :0 sat :143
[2023-03-23 07:52:20] [INFO ] After 19908ms SMT Verify possible using trap constraints in natural domain returned unsat :0 sat :143
Attempting to minimize the solution found.
Minimization took 1 ms.
[2023-03-23 07:52:20] [INFO ] After 25021ms SMT Verify possible using all constraints in natural domain returned unsat :0 sat :143
Parikh walk visited 135 properties in 37788 ms.
Support contains 26 out of 401 places. Attempting structural reductions.
Starting structural reductions in REACHABILITY mode, iteration 0 : 401/401 places, 698/698 transitions.
Drop transitions removed 1 transitions
Reduce isomorphic transitions removed 1 transitions.
Iterating post reduction 0 with 1 rules applied. Total rules applied 1 place count 401 transition count 697
Applied a total of 1 rules in 57 ms. Remains 401 /401 variables (removed 0) and now considering 697/698 (removed 1) transitions.
Finished structural reductions in REACHABILITY mode , in 1 iterations and 58 ms. Remains : 401/401 places, 697/698 transitions.
Incomplete random walk after 1000000 steps, including 237 resets, run finished after 24433 ms. (steps per millisecond=40 ) properties (out of 10) seen :0
Interrupted Best-First random walk after 955826 steps, including 18 resets, run timeout after 5001 ms. (steps per millisecond=191 ) properties seen 0
Incomplete Best-First random walk after 1000000 steps, including 27 resets, run finished after 4779 ms. (steps per millisecond=209 ) properties (out of 10) seen :0
Incomplete Best-First random walk after 1000001 steps, including 31 resets, run finished after 4608 ms. (steps per millisecond=217 ) properties (out of 10) seen :0
Incomplete Best-First random walk after 1000001 steps, including 29 resets, run finished after 4700 ms. (steps per millisecond=212 ) properties (out of 10) seen :0
Interrupted Best-First random walk after 989486 steps, including 26 resets, run timeout after 5001 ms. (steps per millisecond=197 ) properties seen 0
Incomplete Best-First random walk after 1000001 steps, including 30 resets, run finished after 4863 ms. (steps per millisecond=205 ) properties (out of 10) seen :0
Incomplete Best-First random walk after 1000001 steps, including 21 resets, run finished after 4766 ms. (steps per millisecond=209 ) properties (out of 10) seen :0
Incomplete Best-First random walk after 1000001 steps, including 38 resets, run finished after 4785 ms. (steps per millisecond=208 ) properties (out of 10) seen :0
Incomplete Best-First random walk after 1000001 steps, including 14 resets, run finished after 4800 ms. (steps per millisecond=208 ) properties (out of 10) seen :0
Incomplete Best-First random walk after 1000001 steps, including 26 resets, run finished after 4707 ms. (steps per millisecond=212 ) properties (out of 10) seen :0
Finished probabilistic random walk after 706256 steps, run visited all 10 properties in 16607 ms. (steps per millisecond=42 )
Probabilistic random walk after 706256 steps, saw 515839 distinct states, run finished after 16608 ms. (steps per millisecond=42 ) properties seen :10
Able to resolve query QuasiLiveness after proving 202 properties.
FORMULA QuasiLiveness TRUE TECHNIQUES RANDOM_WALK PARIKH_WALK PROBABILISTIC_WALK TOPOLOGICAL INITIAL_STATE
Total runtime 161942 ms.
ITS solved all properties within timeout

BK_STOP 1679558067105

--------------------
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 QuasiLiveness -timeout 180 -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="ShieldRVt-PT-050B"
export BK_EXAMINATION="QuasiLiveness"
export BK_TOOL="smartxred"
export BK_RESULT_DIR="/tmp/BK_RESULTS/OUTPUTS"
export BK_TIME_CONFINEMENT="1800"
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 ShieldRVt-PT-050B, examination is QuasiLiveness"
echo " Time confinement is $BK_TIME_CONFINEMENT seconds"
echo " Memory confinement is 16384 MBytes"
echo " Number of cores is 4"
echo " Run identifier is r441-tajo-167905987000207"
echo "====================================================================="
echo
echo "--------------------"
echo "preparation of the directory to be used:"

tar xzf /home/mcc/BenchKit/INPUTS/ShieldRVt-PT-050B.tgz
mv ShieldRVt-PT-050B execution
cd execution
if [ "QuasiLiveness" = "ReachabilityDeadlock" ] || [ "QuasiLiveness" = "UpperBounds" ] || [ "QuasiLiveness" = "QuasiLiveness" ] || [ "QuasiLiveness" = "StableMarking" ] || [ "QuasiLiveness" = "Liveness" ] || [ "QuasiLiveness" = "OneSafe" ] || [ "QuasiLiveness" = "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 [ "QuasiLiveness" = "UpperBounds" ] ; then
echo "The expected result is a vector of positive values"
echo NUM_VECTOR
elif [ "QuasiLiveness" != "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 "QuasiLiveness.txt" ] ; then
echo "here is the order used to build the result vector(from text file)"
for x in $(grep Property QuasiLiveness.txt | cut -d ' ' -f 2 | sort -u) ; do
echo "FORMULA_NAME $x"
done
elif [ -f "QuasiLiveness.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 '' QuasiLiveness.xml | cut -d '>' -f 2 | cut -d '<' -f 1 | sort -u) ; do
echo "FORMULA_NAME $x"
done
elif [ "QuasiLiveness" = "ReachabilityDeadlock" ] || [ "QuasiLiveness" = "QuasiLiveness" ] || [ "QuasiLiveness" = "StableMarking" ] || [ "QuasiLiveness" = "Liveness" ] || [ "QuasiLiveness" = "OneSafe" ] ; then
echo "FORMULA_NAME QuasiLiveness"
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 ;