About the Execution of GreatSPN+red for AutoFlight-PT-12a
Execution Summary | |||||
Max Memory Used (MB) |
Time wait (ms) | CPU Usage (ms) | I/O Wait (ms) | Computed Result | Execution Status |
382.752 | 8703.00 | 23310.00 | 65.40 | TFFTFFTFTTFTTTTT | normal |
Execution Chart
We display below the execution chart for this examination (boot time has been removed).
Trace from the execution
Formatting '/data/fkordon/mcc2024-input.r025-smll-171620166000159.qcow2', fmt=qcow2 size=4294967296 backing_file=/data/fkordon/mcc2024-input.qcow2 backing_fmt=qcow2 cluster_size=65536 lazy_refcounts=off refcount_bits=16
Waiting for the VM to be ready (probing ssh)
..................
=====================================================================
Generated by BenchKit 2-5568
Executing tool greatspnxred
Input is AutoFlight-PT-12a, examination is ReachabilityFireability
Time confinement is 3600 seconds
Memory confinement is 16384 MBytes
Number of cores is 4
Run identifier is r025-smll-171620166000159
=====================================================================
--------------------
preparation of the directory to be used:
/home/mcc/execution
total 592K
-rw-r--r-- 1 mcc users 7.9K May 14 13:22 CTLCardinality.txt
-rw-r--r-- 1 mcc users 89K May 14 13:22 CTLCardinality.xml
-rw-r--r-- 1 mcc users 5.7K May 14 13:22 CTLFireability.txt
-rw-r--r-- 1 mcc users 54K May 14 13:22 CTLFireability.xml
-rw-r--r-- 1 mcc users 4.2K May 18 16:42 GenericPropertiesDefinition.xml
-rw-r--r-- 1 mcc users 6.6K May 18 16:42 GenericPropertiesVerdict.xml
-rw-r--r-- 1 mcc users 3.7K Apr 22 14:28 LTLCardinality.txt
-rw-r--r-- 1 mcc users 26K Apr 22 14:28 LTLCardinality.xml
-rw-r--r-- 1 mcc users 2.1K May 19 07:12 LTLFireability.txt
-rw-r--r-- 1 mcc users 18K May 19 17:51 LTLFireability.xml
-rw-r--r-- 1 mcc users 14K Apr 12 23:00 ReachabilityCardinality.txt
-rw-r--r-- 1 mcc users 161K Apr 12 23:00 ReachabilityCardinality.xml
-rw-r--r-- 1 mcc users 7.1K Apr 12 22:52 ReachabilityFireability.txt
-rw-r--r-- 1 mcc users 59K Apr 12 22:52 ReachabilityFireability.xml
-rw-r--r-- 1 mcc users 1.6K Apr 22 14:28 UpperBounds.txt
-rw-r--r-- 1 mcc users 3.7K Apr 22 14:28 UpperBounds.xml
-rw-r--r-- 1 mcc users 6 May 18 16:42 equiv_col
-rw-r--r-- 1 mcc users 4 May 18 16:42 instance
-rw-r--r-- 1 mcc users 6 May 18 16:42 iscolored
-rw-r--r-- 1 mcc users 85K May 18 16:42 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 AutoFlight-PT-12a-ReachabilityFireability-2024-00
FORMULA_NAME AutoFlight-PT-12a-ReachabilityFireability-2024-01
FORMULA_NAME AutoFlight-PT-12a-ReachabilityFireability-2024-02
FORMULA_NAME AutoFlight-PT-12a-ReachabilityFireability-2024-03
FORMULA_NAME AutoFlight-PT-12a-ReachabilityFireability-2024-04
FORMULA_NAME AutoFlight-PT-12a-ReachabilityFireability-2024-05
FORMULA_NAME AutoFlight-PT-12a-ReachabilityFireability-2024-06
FORMULA_NAME AutoFlight-PT-12a-ReachabilityFireability-2024-07
FORMULA_NAME AutoFlight-PT-12a-ReachabilityFireability-2024-08
FORMULA_NAME AutoFlight-PT-12a-ReachabilityFireability-2024-09
FORMULA_NAME AutoFlight-PT-12a-ReachabilityFireability-2024-10
FORMULA_NAME AutoFlight-PT-12a-ReachabilityFireability-2024-11
FORMULA_NAME AutoFlight-PT-12a-ReachabilityFireability-2024-12
FORMULA_NAME AutoFlight-PT-12a-ReachabilityFireability-2024-13
FORMULA_NAME AutoFlight-PT-12a-ReachabilityFireability-2024-14
FORMULA_NAME AutoFlight-PT-12a-ReachabilityFireability-2024-15
=== Now, execution of the tool begins
BK_START 1716293343386
Invoking MCC driver with
BK_TOOL=greatspnxred
BK_EXAMINATION=ReachabilityFireability
BK_BIN_PATH=/home/mcc/BenchKit/bin/
BK_TIME_CONFINEMENT=3600
BK_INPUT=AutoFlight-PT-12a
BK_MEMORY_CONFINEMENT=16384
Applying reductions before tool greatspn
Invoking reducer
Running Version 202405141337
[2024-05-21 12:09:05] [INFO ] Running its-tools with arguments : [-pnfolder, /home/mcc/execution, -examination, ReachabilityFireability, -timeout, 360, -rebuildPNML]
[2024-05-21 12:09:05] [INFO ] Parsing pnml file : /home/mcc/execution/model.pnml
[2024-05-21 12:09:05] [INFO ] Load time of PNML (sax parser for PT used): 143 ms
[2024-05-21 12:09:05] [INFO ] Transformed 307 places.
[2024-05-21 12:09:05] [INFO ] Transformed 305 transitions.
[2024-05-21 12:09:05] [INFO ] Found NUPN structural information;
[2024-05-21 12:09:05] [INFO ] Parsed PT model containing 307 places and 305 transitions and 980 arcs in 299 ms.
Parsed 16 properties from file /home/mcc/execution/ReachabilityFireability.xml in 21 ms.
Working with output stream class java.io.PrintStream
Ensure Unique test removed 60 transitions
Reduce redundant transitions removed 60 transitions.
RANDOM walk for 40000 steps (710 resets) in 2685 ms. (14 steps per ms) remains 5/16 properties
FORMULA AutoFlight-PT-12a-ReachabilityFireability-2024-15 TRUE TECHNIQUES TOPOLOGICAL RANDOM_WALK
FORMULA AutoFlight-PT-12a-ReachabilityFireability-2024-14 TRUE TECHNIQUES TOPOLOGICAL RANDOM_WALK
FORMULA AutoFlight-PT-12a-ReachabilityFireability-2024-13 TRUE TECHNIQUES TOPOLOGICAL RANDOM_WALK
FORMULA AutoFlight-PT-12a-ReachabilityFireability-2024-12 TRUE TECHNIQUES TOPOLOGICAL RANDOM_WALK
FORMULA AutoFlight-PT-12a-ReachabilityFireability-2024-11 TRUE TECHNIQUES TOPOLOGICAL RANDOM_WALK
FORMULA AutoFlight-PT-12a-ReachabilityFireability-2024-09 TRUE TECHNIQUES TOPOLOGICAL RANDOM_WALK
FORMULA AutoFlight-PT-12a-ReachabilityFireability-2024-08 TRUE TECHNIQUES TOPOLOGICAL RANDOM_WALK
FORMULA AutoFlight-PT-12a-ReachabilityFireability-2024-07 FALSE TECHNIQUES TOPOLOGICAL RANDOM_WALK
FORMULA AutoFlight-PT-12a-ReachabilityFireability-2024-04 FALSE TECHNIQUES TOPOLOGICAL RANDOM_WALK
FORMULA AutoFlight-PT-12a-ReachabilityFireability-2024-03 TRUE TECHNIQUES TOPOLOGICAL RANDOM_WALK
FORMULA AutoFlight-PT-12a-ReachabilityFireability-2024-00 TRUE TECHNIQUES TOPOLOGICAL RANDOM_WALK
BEST_FIRST walk for 40004 steps (44 resets) in 704 ms. (56 steps per ms) remains 5/5 properties
BEST_FIRST walk for 40004 steps (48 resets) in 1399 ms. (28 steps per ms) remains 5/5 properties
BEST_FIRST walk for 40003 steps (42 resets) in 532 ms. (75 steps per ms) remains 5/5 properties
BEST_FIRST walk for 40004 steps (42 resets) in 207 ms. (192 steps per ms) remains 5/5 properties
BEST_FIRST walk for 40003 steps (44 resets) in 1048 ms. (38 steps per ms) remains 4/5 properties
FORMULA AutoFlight-PT-12a-ReachabilityFireability-2024-10 FALSE TECHNIQUES TOPOLOGICAL BESTFIRST_WALK
// Phase 1: matrix 245 rows 307 cols
[2024-05-21 12:09:07] [INFO ] Computed 76 invariants in 38 ms
[2024-05-21 12:09:07] [INFO ] State equation strengthened by 60 read => feed constraints.
All remaining problems are real, not stopping.
At refinement iteration 0 (INCLUDED_ONLY) 0/129 variables, 129/129 constraints. Problems are: Problem set: 0 solved, 4 unsolved
At refinement iteration 1 (INCLUDED_ONLY) 0/129 variables, 0/129 constraints. Problems are: Problem set: 0 solved, 4 unsolved
At refinement iteration 2 (OVERLAPS) 103/232 variables, 58/187 constraints. Problems are: Problem set: 0 solved, 4 unsolved
Problem AutoFlight-PT-12a-ReachabilityFireability-2024-05 is UNSAT
FORMULA AutoFlight-PT-12a-ReachabilityFireability-2024-05 FALSE TECHNIQUES SMT_REFINEMENT
At refinement iteration 3 (INCLUDED_ONLY) 0/232 variables, 103/290 constraints. Problems are: Problem set: 1 solved, 3 unsolved
At refinement iteration 4 (INCLUDED_ONLY) 0/232 variables, 0/290 constraints. Problems are: Problem set: 1 solved, 3 unsolved
At refinement iteration 5 (OVERLAPS) 29/261 variables, 17/307 constraints. Problems are: Problem set: 1 solved, 3 unsolved
At refinement iteration 6 (INCLUDED_ONLY) 0/261 variables, 29/336 constraints. Problems are: Problem set: 1 solved, 3 unsolved
At refinement iteration 7 (INCLUDED_ONLY) 0/261 variables, 0/336 constraints. Problems are: Problem set: 1 solved, 3 unsolved
Problem AutoFlight-PT-12a-ReachabilityFireability-2024-01 is UNSAT
FORMULA AutoFlight-PT-12a-ReachabilityFireability-2024-01 FALSE TECHNIQUES SMT_REFINEMENT
At refinement iteration 8 (OVERLAPS) 46/307 variables, 1/337 constraints. Problems are: Problem set: 2 solved, 2 unsolved
At refinement iteration 9 (INCLUDED_ONLY) 0/307 variables, 46/383 constraints. Problems are: Problem set: 2 solved, 2 unsolved
At refinement iteration 10 (INCLUDED_ONLY) 0/307 variables, 0/383 constraints. Problems are: Problem set: 2 solved, 2 unsolved
At refinement iteration 11 (OVERLAPS) 245/552 variables, 307/690 constraints. Problems are: Problem set: 2 solved, 2 unsolved
At refinement iteration 12 (INCLUDED_ONLY) 0/552 variables, 60/750 constraints. Problems are: Problem set: 2 solved, 2 unsolved
At refinement iteration 13 (INCLUDED_ONLY) 0/552 variables, 0/750 constraints. Problems are: Problem set: 2 solved, 2 unsolved
At refinement iteration 14 (OVERLAPS) 0/552 variables, 0/750 constraints. Problems are: Problem set: 2 solved, 2 unsolved
No progress, stopping.
After SMT solving in domain Real declared 552/552 variables, and 750 constraints, problems are : Problem set: 2 solved, 2 unsolved in 1134 ms.
Refiners :[Domain max(s): 307/307 constraints, Positive P Invariants (semi-flows): 75/75 constraints, Generalized P Invariants (flows): 1/1 constraints, State Equation: 307/307 constraints, ReadFeed: 60/60 constraints, PredecessorRefiner: 4/4 constraints, Known Traps: 0/0 constraints]
Escalating to Integer solving :Problem set: 2 solved, 2 unsolved
At refinement iteration 0 (INCLUDED_ONLY) 0/90 variables, 90/90 constraints. Problems are: Problem set: 2 solved, 2 unsolved
At refinement iteration 1 (INCLUDED_ONLY) 0/90 variables, 0/90 constraints. Problems are: Problem set: 2 solved, 2 unsolved
At refinement iteration 2 (OVERLAPS) 116/206 variables, 49/139 constraints. Problems are: Problem set: 2 solved, 2 unsolved
At refinement iteration 3 (INCLUDED_ONLY) 0/206 variables, 116/255 constraints. Problems are: Problem set: 2 solved, 2 unsolved
At refinement iteration 4 (INCLUDED_ONLY) 0/206 variables, 0/255 constraints. Problems are: Problem set: 2 solved, 2 unsolved
At refinement iteration 5 (OVERLAPS) 51/257 variables, 26/281 constraints. Problems are: Problem set: 2 solved, 2 unsolved
At refinement iteration 6 (INCLUDED_ONLY) 0/257 variables, 51/332 constraints. Problems are: Problem set: 2 solved, 2 unsolved
At refinement iteration 7 (INCLUDED_ONLY) 0/257 variables, 0/332 constraints. Problems are: Problem set: 2 solved, 2 unsolved
At refinement iteration 8 (OVERLAPS) 50/307 variables, 1/333 constraints. Problems are: Problem set: 2 solved, 2 unsolved
At refinement iteration 9 (INCLUDED_ONLY) 0/307 variables, 50/383 constraints. Problems are: Problem set: 2 solved, 2 unsolved
[2024-05-21 12:09:09] [INFO ] Deduced a trap composed of 127 places in 149 ms of which 29 ms to minimize.
[2024-05-21 12:09:09] [INFO ] Deduced a trap composed of 128 places in 120 ms of which 2 ms to minimize.
[2024-05-21 12:09:09] [INFO ] Deduced a trap composed of 135 places in 123 ms of which 3 ms to minimize.
[2024-05-21 12:09:09] [INFO ] Deduced a trap composed of 136 places in 117 ms of which 3 ms to minimize.
At refinement iteration 10 (INCLUDED_ONLY) 0/307 variables, 4/387 constraints. Problems are: Problem set: 2 solved, 2 unsolved
At refinement iteration 11 (INCLUDED_ONLY) 0/307 variables, 0/387 constraints. Problems are: Problem set: 2 solved, 2 unsolved
At refinement iteration 12 (OVERLAPS) 245/552 variables, 307/694 constraints. Problems are: Problem set: 2 solved, 2 unsolved
At refinement iteration 13 (INCLUDED_ONLY) 0/552 variables, 60/754 constraints. Problems are: Problem set: 2 solved, 2 unsolved
At refinement iteration 14 (INCLUDED_ONLY) 0/552 variables, 2/756 constraints. Problems are: Problem set: 2 solved, 2 unsolved
[2024-05-21 12:09:10] [INFO ] Deduced a trap composed of 126 places in 96 ms of which 2 ms to minimize.
[2024-05-21 12:09:10] [INFO ] Deduced a trap composed of 132 places in 89 ms of which 3 ms to minimize.
[2024-05-21 12:09:10] [INFO ] Deduced a trap composed of 129 places in 89 ms of which 2 ms to minimize.
At refinement iteration 15 (INCLUDED_ONLY) 0/552 variables, 3/759 constraints. Problems are: Problem set: 2 solved, 2 unsolved
[2024-05-21 12:09:10] [INFO ] Deduced a trap composed of 137 places in 91 ms of which 2 ms to minimize.
At refinement iteration 16 (INCLUDED_ONLY) 0/552 variables, 1/760 constraints. Problems are: Problem set: 2 solved, 2 unsolved
[2024-05-21 12:09:10] [INFO ] Deduced a trap composed of 131 places in 82 ms of which 2 ms to minimize.
At refinement iteration 17 (INCLUDED_ONLY) 0/552 variables, 1/761 constraints. Problems are: Problem set: 2 solved, 2 unsolved
At refinement iteration 18 (INCLUDED_ONLY) 0/552 variables, 0/761 constraints. Problems are: Problem set: 2 solved, 2 unsolved
At refinement iteration 19 (OVERLAPS) 0/552 variables, 0/761 constraints. Problems are: Problem set: 2 solved, 2 unsolved
No progress, stopping.
After SMT solving in domain Int declared 552/552 variables, and 761 constraints, problems are : Problem set: 2 solved, 2 unsolved in 2376 ms.
Refiners :[Domain max(s): 307/307 constraints, Positive P Invariants (semi-flows): 75/75 constraints, Generalized P Invariants (flows): 1/1 constraints, State Equation: 307/307 constraints, ReadFeed: 60/60 constraints, PredecessorRefiner: 2/4 constraints, Known Traps: 9/9 constraints]
After SMT, in 3705ms problems are : Problem set: 2 solved, 2 unsolved
FORMULA AutoFlight-PT-12a-ReachabilityFireability-2024-02 FALSE TECHNIQUES PARIKH_WALK
Parikh walk visited 1 properties in 159 ms.
Support contains 28 out of 307 places. Attempting structural reductions.
Starting structural reductions in REACHABILITY mode, iteration 0 : 307/307 places, 245/245 transitions.
Drop transitions (Trivial Post-Agglo cleanup.) removed 29 transitions
Trivial Post-agglo rules discarded 29 transitions
Performed 29 trivial Post agglomeration. Transition count delta: 29
Iterating post reduction 0 with 29 rules applied. Total rules applied 29 place count 307 transition count 216
Reduce places removed 29 places and 0 transitions.
Performed 1 Post agglomeration using F-continuation condition.Transition count delta: 1
Iterating post reduction 1 with 30 rules applied. Total rules applied 59 place count 278 transition count 215
Reduce places removed 1 places and 0 transitions.
Iterating post reduction 2 with 1 rules applied. Total rules applied 60 place count 277 transition count 215
Performed 12 Pre agglomeration using Quasi-Persistent + Divergent Free condition..
Pre-agglomeration after 3 with 12 Pre rules applied. Total rules applied 60 place count 277 transition count 203
Deduced a syphon composed of 12 places in 6 ms
Reduce places removed 12 places and 0 transitions.
Iterating global reduction 3 with 24 rules applied. Total rules applied 84 place count 265 transition count 203
Performed 16 Post agglomeration using F-continuation condition.Transition count delta: 16
Deduced a syphon composed of 16 places in 1 ms
Reduce places removed 16 places and 0 transitions.
Iterating global reduction 3 with 32 rules applied. Total rules applied 116 place count 249 transition count 187
Free-agglomeration rule applied 18 times.
Iterating global reduction 3 with 18 rules applied. Total rules applied 134 place count 249 transition count 169
Reduce places removed 18 places and 0 transitions.
Iterating post reduction 3 with 18 rules applied. Total rules applied 152 place count 231 transition count 169
Applied a total of 152 rules in 123 ms. Remains 231 /307 variables (removed 76) and now considering 169/245 (removed 76) transitions.
Finished structural reductions in REACHABILITY mode , in 1 iterations and 141 ms. Remains : 231/307 places, 169/245 transitions.
RANDOM walk for 40000 steps (1134 resets) in 1236 ms. (32 steps per ms) remains 1/1 properties
BEST_FIRST walk for 32873 steps (187 resets) in 211 ms. (155 steps per ms) remains 0/1 properties
FORMULA AutoFlight-PT-12a-ReachabilityFireability-2024-06 TRUE TECHNIQUES TOPOLOGICAL BESTFIRST_WALK
All properties solved without resorting to model-checking.
Total runtime 6923 ms.
ITS solved all properties within timeout
BK_STOP 1716293352089
--------------------
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:
++ perl -pe 's/.*\.//g'
++ sed s/.jar//
++ ls /home/mcc/BenchKit/bin//../reducer/bin//../../itstools//itstools/plugins/fr.lip6.move.gal.application.pnmcc_1.0.0.202405141337.jar
+ VERSION=202405141337
+ echo 'Running Version 202405141337'
+ /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="AutoFlight-PT-12a"
export BK_EXAMINATION="ReachabilityFireability"
export BK_TOOL="greatspnxred"
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 2-5568"
echo " Executing tool greatspnxred"
echo " Input is AutoFlight-PT-12a, 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 r025-smll-171620166000159"
echo "====================================================================="
echo
echo "--------------------"
echo "preparation of the directory to be used:"
tar xzf /home/mcc/BenchKit/INPUTS/AutoFlight-PT-12a.tgz
mv AutoFlight-PT-12a 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 '
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 ;