Running: ./testmodel.py --libraries=/home/hudson/saved_omc/libraries/.openmodelica/libraries/ --ompython_omhome=/usr Buildings_maint.7.0.x_Buildings.Controls.OBC.ASHRAE.G36_PR1.AHUs.SingleZone.VAV.Validation.CoolingCoil.conf.json
loadFile("/home/hudson/saved_omc/libraries/.openmodelica/libraries/ModelicaServices 4.0.0+maint.om/package.mo", uses=false)
loadFile("/home/hudson/saved_omc/libraries/.openmodelica/libraries/Complex 4.0.0+maint.om/package.mo", uses=false)
loadFile("/home/hudson/saved_omc/libraries/.openmodelica/libraries/Modelica 3.2.3+maint.om/package.mo", uses=false)
loadFile("/home/hudson/saved_omc/libraries/.openmodelica/libraries/Buildings 7.0.3-maint.7.0.x/package.mo", uses=false)
Using package Buildings with version 7.0.3 (/home/hudson/saved_omc/libraries/.openmodelica/libraries/Buildings 7.0.3-maint.7.0.x/package.mo)
Using package Modelica with version 3.2.3 (/home/hudson/saved_omc/libraries/.openmodelica/libraries/Modelica 3.2.3+maint.om/package.mo)
Using package Complex with version 4.0.0 (/home/hudson/saved_omc/libraries/.openmodelica/libraries/Complex 4.0.0+maint.om/package.mo)
Using package ModelicaServices with version 4.0.0 (/home/hudson/saved_omc/libraries/.openmodelica/libraries/ModelicaServices 4.0.0+maint.om/package.mo)
Running command: translateModel(Buildings.Controls.OBC.ASHRAE.G36_PR1.AHUs.SingleZone.VAV.Validation.CoolingCoil,tolerance=1e-06,outputFormat="empty",numberOfIntervals=92,variableFilter="",fileNamePrefix="Buildings_maint.7.0.x_Buildings.Controls.OBC.ASHRAE.G36_PR1.AHUs.SingleZone.VAV.Validation.CoolingCoil")
translateModel(Buildings.Controls.OBC.ASHRAE.G36_PR1.AHUs.SingleZone.VAV.Validation.CoolingCoil,tolerance=1e-06,outputFormat="empty",numberOfIntervals=92,variableFilter="",fileNamePrefix="Buildings_maint.7.0.x_Buildings.Controls.OBC.ASHRAE.G36_PR1.AHUs.SingleZone.VAV.Validation.CoolingCoil")
Notification: Performance of loadFile(/home/hudson/saved_omc/libraries/.openmodelica/libraries/ModelicaServices 4.0.0+maint.om/package.mo): time 0.0009199/0.0009199, allocations: 84.38 kB / 15.06 MB, free: 1.09 MB / 14.72 MB
Notification: Performance of loadFile(/home/hudson/saved_omc/libraries/.openmodelica/libraries/Complex 4.0.0+maint.om/package.mo): time 0.001296/0.001295, allocations: 168.7 kB / 15.95 MB, free: 204 kB / 14.72 MB
Notification: Performance of loadFile(/home/hudson/saved_omc/libraries/.openmodelica/libraries/Modelica 3.2.3+maint.om/package.mo): time 1.673/1.673, allocations: 205.4 MB / 222.1 MB, free: 5.637 MB / 174.1 MB
Notification: Performance of loadFile(/home/hudson/saved_omc/libraries/.openmodelica/libraries/Buildings 7.0.3-maint.7.0.x/package.mo): time 1.614/1.614, allocations: 252 MB / 0.5102 GB, free: 4.785 MB / 414.1 MB
Notification: Modelica requested package Complex of version 3.2.3. Complex 4.0.0 is used instead which states that it is fully compatible without conversion script needed.
Notification: Modelica requested package ModelicaServices of version 3.2.3. ModelicaServices 4.0.0 is used instead which states that it is fully compatible without conversion script needed.
Notification: Performance of FrontEnd - loaded program: time 0.0005889/0.000589, allocations: 12 kB / 0.6243 GB, free: 1.059 MB / 0.5137 GB
Notification: Performance of FrontEnd - Absyn->SCode: time 0.6398/0.6404, allocations: 106.3 MB / 0.7282 GB, free: 11.42 MB / 0.545 GB
Notification: Performance of NFInst.instantiate(Buildings.Controls.OBC.ASHRAE.G36_PR1.AHUs.SingleZone.VAV.Validation.CoolingCoil): time 0.002687/0.6431, allocations: 1.987 MB / 0.7301 GB, free: 9.418 MB / 0.545 GB
Notification: Performance of NFInst.instExpressions: time 0.001615/0.6448, allocations: 0.8349 MB / 0.7309 GB, free: 8.574 MB / 0.545 GB
Notification: Performance of NFInst.updateImplicitVariability: time 0.0002266/0.645, allocations: 15.94 kB / 0.731 GB, free: 8.559 MB / 0.545 GB
Notification: Performance of NFTyping.typeComponents: time 0.0001995/0.6452, allocations: 35.66 kB / 0.731 GB, free: 8.523 MB / 0.545 GB
Notification: Performance of NFTyping.typeBindings: time 0.0001144/0.6453, allocations: 27.73 kB / 0.731 GB, free: 8.496 MB / 0.545 GB
Notification: Performance of NFTyping.typeClassSections: time 0.00032/0.6457, allocations: 87.84 kB / 0.7311 GB, free: 8.41 MB / 0.545 GB
Notification: Performance of NFFlatten.flatten: time 0.000335/0.646, allocations: 336.2 kB / 0.7314 GB, free: 8.082 MB / 0.545 GB
Notification: Performance of NFFlatten.resolveConnections: time 0.0002647/0.6463, allocations: 128 kB / 0.7315 GB, free: 7.953 MB / 0.545 GB
Notification: Performance of NFEvalConstants.evaluate: time 0.000122/0.6464, allocations: 87.52 kB / 0.7316 GB, free: 7.867 MB / 0.545 GB
Notification: Performance of NFSimplifyModel.simplify: time 0.0001748/0.6466, allocations: 103.3 kB / 0.7317 GB, free: 7.766 MB / 0.545 GB
Notification: Performance of NFPackage.collectConstants: time 3.941e-05/0.6467, allocations: 8 kB / 0.7317 GB, free: 7.758 MB / 0.545 GB
Notification: Performance of NFFlatten.collectFunctions: time 3.081e-05/0.6467, allocations: 8 kB / 0.7317 GB, free: 7.75 MB / 0.545 GB
Notification: Performance of NFScalarize.scalarize: time 5.886e-05/0.6468, allocations: 39.78 kB / 0.7318 GB, free: 7.711 MB / 0.545 GB
Notification: Performance of NFVerifyModel.verify: time 8.037e-05/0.6468, allocations: 77.52 kB / 0.7318 GB, free: 7.629 MB / 0.545 GB
Notification: Performance of NFConvertDAE.convert: time 0.0004422/0.6473, allocations: 392.9 kB / 0.7322 GB, free: 7.246 MB / 0.545 GB
Notification: Performance of FrontEnd - DAE generated: time 9.398e-06/0.6473, allocations: 0 / 0.7322 GB, free: 7.246 MB / 0.545 GB
Notification: Performance of FrontEnd: time 3.898e-06/0.6473, allocations: 0 / 0.7322 GB, free: 7.246 MB / 0.545 GB
Notification: Performance of Transformations before backend: time 8.145e-06/0.6473, allocations: 0 / 0.7322 GB, free: 7.246 MB / 0.545 GB
Notification: Model statistics after passing the front-end and creating the data structures used by the back-end:
 * Number of equations: 62
 * Number of variables: 62
Notification: Performance of Generate backend data structure: time 0.001376/0.6487, allocations: 0.5884 MB / 0.7328 GB, free: 6.609 MB / 0.545 GB
Notification: Performance of prepare preOptimizeDAE: time 6.44e-05/0.6488, allocations: 12.03 kB / 0.7328 GB, free: 6.598 MB / 0.545 GB
Notification: Performance of preOpt normalInlineFunction (simulation): time 0.0001226/0.6489, allocations: 43.47 kB / 0.7329 GB, free: 6.555 MB / 0.545 GB
Notification: Performance of preOpt evaluateParameters (simulation): time 0.0006286/0.6496, allocations: 326 kB / 0.7332 GB, free: 6.199 MB / 0.545 GB
Notification: Performance of preOpt simplifyIfEquations (simulation): time 4.757e-05/0.6496, allocations: 20.56 kB / 0.7332 GB, free: 6.18 MB / 0.545 GB
Notification: Performance of preOpt expandDerOperator (simulation): time 4.721e-05/0.6497, allocations: 27.98 kB / 0.7332 GB, free: 6.152 MB / 0.545 GB
Notification: Performance of preOpt clockPartitioning (simulation): time 0.0007524/0.6504, allocations: 311.7 kB / 0.7335 GB, free: 5.836 MB / 0.545 GB
Notification: Performance of preOpt findStateOrder (simulation): time 1.46e-05/0.6505, allocations: 0 / 0.7335 GB, free: 5.836 MB / 0.545 GB
Notification: Performance of preOpt replaceEdgeChange (simulation): time 3.403e-05/0.6505, allocations: 8 kB / 0.7335 GB, free: 5.828 MB / 0.545 GB
Notification: Performance of preOpt inlineArrayEqn (simulation): time 1.345e-05/0.6505, allocations: 11.94 kB / 0.7335 GB, free: 5.816 MB / 0.545 GB
Notification: Performance of preOpt removeEqualRHS (simulation): time 0.0006725/0.6512, allocations: 266 kB / 0.7338 GB, free: 5.559 MB / 0.545 GB
Notification: Performance of preOpt removeSimpleEquations (simulation): time 0.001854/0.6531, allocations: 0.9962 MB / 0.7348 GB, free: 4.492 MB / 0.545 GB
Notification: Performance of preOpt comSubExp (simulation): time 0.0005441/0.6536, allocations: 226.7 kB / 0.735 GB, free: 4.262 MB / 0.545 GB
Notification: Performance of preOpt resolveLoops (simulation): time 0.0002606/0.6539, allocations: 100.8 kB / 0.7351 GB, free: 4.16 MB / 0.545 GB
Notification: Performance of preOpt evalFunc (simulation): time 2.55e-05/0.6539, allocations: 7.938 kB / 0.7351 GB, free: 4.152 MB / 0.545 GB
Notification: Performance of preOpt encapsulateWhenConditions (simulation): time 0.0004135/0.6544, allocations: 155.2 kB / 0.7352 GB, free: 3.988 MB / 0.545 GB
Notification: Performance of pre-optimization done (n=15): time 4.399e-06/0.6544, allocations: 4 kB / 0.7352 GB, free: 3.984 MB / 0.545 GB
Notification: Performance of matching and sorting (n=15): time 0.0008598/0.6552, allocations: 325.1 kB / 0.7355 GB, free: 3.66 MB / 0.545 GB
Notification: Performance of inlineWhenForInitialization (initialization): time 6.06e-05/0.6553, allocations: 89.09 kB / 0.7356 GB, free: 3.555 MB / 0.545 GB
Notification: Performance of selectInitializationVariablesDAE (initialization): time 0.0003332/0.6557, allocations: 300.5 kB / 0.7359 GB, free: 3.25 MB / 0.545 GB
Notification: Performance of collectPreVariables (initialization): time 3.038e-05/0.6557, allocations: 33.7 kB / 0.7359 GB, free: 3.211 MB / 0.545 GB
Notification: Performance of collectInitialEqns (initialization): time 0.0001738/0.6559, allocations: 195.9 kB / 0.7361 GB, free: 3.016 MB / 0.545 GB
Notification: Performance of collectInitialBindings (initialization): time 4.335e-05/0.6559, allocations: 43.45 kB / 0.7362 GB, free: 2.973 MB / 0.545 GB
Notification: Performance of simplifyInitialFunctions (initialization): time 1.352e-05/0.6559, allocations: 4 kB / 0.7362 GB, free: 2.969 MB / 0.545 GB
Notification: Performance of setup shared object (initialization): time 0.0001996/0.6561, allocations: 338.8 kB / 0.7365 GB, free: 2.629 MB / 0.545 GB
Notification: Performance of preBalanceInitialSystem (initialization): time 0.0002789/0.6564, allocations: 103.9 kB / 0.7366 GB, free: 2.527 MB / 0.545 GB
Notification: Performance of partitionIndependentBlocks (initialization): time 0.0003399/0.6568, allocations: 154.1 kB / 0.7367 GB, free: 2.355 MB / 0.545 GB
Notification: Performance of analyzeInitialSystem (initialization): time 0.0002894/0.6571, allocations: 103.7 kB / 0.7368 GB, free: 2.258 MB / 0.545 GB
Notification: Performance of solveInitialSystemEqSystem (initialization): time 2.796e-06/0.6571, allocations: 4 kB / 0.7368 GB, free: 2.254 MB / 0.545 GB
Notification: Performance of matching and sorting (n=25) (initialization): time 0.0006961/0.6578, allocations: 307.4 kB / 0.7371 GB, free: 1.949 MB / 0.545 GB
Notification: Performance of prepare postOptimizeDAE: time 9.029e-05/0.6579, allocations: 122.1 kB / 0.7373 GB, free: 1.812 MB / 0.545 GB
Notification: Performance of postOpt simplifyComplexFunction (initialization): time 8.356e-06/0.6579, allocations: 4 kB / 0.7373 GB, free: 1.809 MB / 0.545 GB
Notification: Performance of postOpt tearingSystem (initialization): time 1.573e-05/0.6579, allocations: 0 / 0.7373 GB, free: 1.809 MB / 0.545 GB
Notification: Performance of postOpt solveSimpleEquations (initialization): time 0.0002604/0.6582, allocations: 63.89 kB / 0.7373 GB, free: 1.746 MB / 0.545 GB
Notification: Performance of postOpt calculateStrongComponentJacobians (initialization): time 8.837e-06/0.6582, allocations: 0 / 0.7373 GB, free: 1.746 MB / 0.545 GB
Notification: Performance of postOpt simplifyAllExpressions (initialization): time 0.000216/0.6584, allocations: 59.64 kB / 0.7374 GB, free: 1.688 MB / 0.545 GB
Notification: Performance of postOpt collapseArrayExpressions (initialization): time 2.206e-05/0.6585, allocations: 12 kB / 0.7374 GB, free: 1.676 MB / 0.545 GB
Notification: Performance of prepare postOptimizeDAE: time 6.622e-06/0.6585, allocations: 4 kB / 0.7374 GB, free: 1.672 MB / 0.545 GB
Notification: Performance of postOpt replaceHomotopyWithSimplified (initialization): time 0.0004945/0.659, allocations: 214.1 kB / 0.7376 GB, free: 1.465 MB / 0.545 GB
Notification: Performance of postOpt simplifyComplexFunction (initialization): time 2.244e-06/0.659, allocations: 0 / 0.7376 GB, free: 1.465 MB / 0.545 GB
Notification: Performance of postOpt tearingSystem (initialization): time 4.538e-06/0.659, allocations: 4 kB / 0.7376 GB, free: 1.461 MB / 0.545 GB
Notification: Performance of postOpt solveSimpleEquations (initialization): time 0.0001975/0.6592, allocations: 60.02 kB / 0.7377 GB, free: 1.402 MB / 0.545 GB
Notification: Performance of postOpt calculateStrongComponentJacobians (initialization): time 4.569e-06/0.6592, allocations: 4 kB / 0.7377 GB, free: 1.398 MB / 0.545 GB
Notification: Performance of postOpt simplifyAllExpressions (initialization): time 0.0001717/0.6594, allocations: 39.77 kB / 0.7377 GB, free: 1.359 MB / 0.545 GB
Notification: Performance of postOpt collapseArrayExpressions (initialization): time 1.742e-05/0.6594, allocations: 15.94 kB / 0.7377 GB, free: 1.344 MB / 0.545 GB
Notification: Model statistics after passing the back-end for initialization:
 * Number of independent subsystems: 5
 * Number of states: 0 ()
 * Number of discrete variables: 9 (cooCoi.conInt.y,$whenCondition1,cooCoi.intEqu.y,cooCoi.and2.y,$PRE.zonSta.T_start,zonSta.T_start,$PRE.zonSta.count,zonSta.count,reaToInt.y)
 * Number of discrete states: 0 ()
 * Number of clocked states: 0 ()
 * Top-level inputs: 0
Notification: Strong component statistics for initialization (25):
 * Single equations (assignments): 25
 * Array equations: 0
 * Algorithm blocks: 0
 * Record equations: 0
 * When equations: 0
 * If-equations: 0
 * Equation systems (linear and non-linear blocks): 0
 * Torn equation systems: 0
 * Mixed (continuous/discrete) equation systems: 0
Notification: Performance of prepare postOptimizeDAE: time 0.0002105/0.6596, allocations: 225.1 kB / 0.7379 GB, free: 1.113 MB / 0.545 GB
Notification: Performance of postOpt lateInlineFunction (simulation): time 3.679e-05/0.6597, allocations: 27.72 kB / 0.738 GB, free: 1.086 MB / 0.545 GB
Notification: Performance of postOpt wrapFunctionCalls (simulation): time 6.973e-05/0.6598, allocations: 29.97 kB / 0.738 GB, free: 1.055 MB / 0.545 GB
Notification: Performance of postOpt inlineArrayEqn (simulation): time 4.338e-06/0.6598, allocations: 0 / 0.738 GB, free: 1.055 MB / 0.545 GB
Notification: Performance of postOpt constantLinearSystem (simulation): time 6.462e-06/0.6598, allocations: 0 / 0.738 GB, free: 1.055 MB / 0.545 GB
Notification: Performance of postOpt simplifysemiLinear (simulation): time 5.8e-06/0.6598, allocations: 4 kB / 0.738 GB, free: 1.051 MB / 0.545 GB
Notification: Performance of postOpt removeSimpleEquations (simulation): time 0.0003554/0.6602, allocations: 329.3 kB / 0.7383 GB, free: 0.6797 MB / 0.545 GB
Notification: Performance of postOpt simplifyComplexFunction (simulation): time 3.196e-06/0.6602, allocations: 4 kB / 0.7383 GB, free: 0.6758 MB / 0.545 GB
Notification: Performance of postOpt solveSimpleEquations (simulation): time 0.0001745/0.6603, allocations: 47.97 kB / 0.7383 GB, free: 0.6289 MB / 0.545 GB
Notification: Performance of postOpt tearingSystem (simulation): time 4.599e-06/0.6604, allocations: 3.984 kB / 0.7384 GB, free: 0.625 MB / 0.545 GB
Notification: Performance of postOpt inputDerivativesUsed (simulation): time 1.607e-05/0.6604, allocations: 7.922 kB / 0.7384 GB, free: 0.6172 MB / 0.545 GB
Notification: Performance of postOpt calculateStrongComponentJacobians (simulation): time 1.724e-06/0.6604, allocations: 0 / 0.7384 GB, free: 0.6172 MB / 0.545 GB
Notification: Performance of postOpt calculateStateSetsJacobians (simulation): time 1.113e-06/0.6604, allocations: 0 / 0.7384 GB, free: 0.6172 MB / 0.545 GB
Notification: Performance of postOpt symbolicJacobian (simulation): time 0.0006866/0.6611, allocations: 279.5 kB / 0.7386 GB, free: 336 kB / 0.545 GB
Notification: Performance of postOpt removeConstants (simulation): time 7.481e-05/0.6612, allocations: 112.7 kB / 0.7387 GB, free: 204 kB / 0.545 GB
Notification: Performance of postOpt simplifyTimeIndepFuncCalls (simulation): time 3.836e-05/0.6612, allocations: 4 kB / 0.7387 GB, free: 200 kB / 0.545 GB
Notification: Performance of postOpt simplifyAllExpressions (simulation): time 0.0001621/0.6614, allocations: 27.97 kB / 0.7388 GB, free: 172 kB / 0.545 GB
Notification: Performance of postOpt findZeroCrossings (simulation): time 8.991e-05/0.6615, allocations: 27.95 kB / 0.7388 GB, free: 144 kB / 0.545 GB
Notification: Performance of postOpt collapseArrayExpressions (simulation): time 1.476e-05/0.6615, allocations: 4 kB / 0.7388 GB, free: 140 kB / 0.545 GB
Notification: Performance of sorting global known variables: time 0.0002444/0.6618, allocations: 219.1 kB / 0.739 GB, free: 15.92 MB / 0.5606 GB
Notification: Performance of sort global known variables: time 1.61e-07/0.6618, allocations: 0 / 0.739 GB, free: 15.92 MB / 0.5606 GB
Notification: Performance of remove unused functions: time 0.000359/0.6621, allocations: 87.69 kB / 0.7391 GB, free: 15.84 MB / 0.5606 GB
Notification: Model statistics after passing the back-end for simulation:
 * Number of independent subsystems: 1
 * Number of states: 0 ()
 * Number of discrete variables: 6 ($whenCondition1,cooCoi.intEqu.y,cooCoi.and2.y,zonSta.T_start,zonSta.count,reaToInt.y)
 * Number of discrete states: 1 (zonSta.count)
 * Number of clocked states: 0 ()
 * Top-level inputs: 0
Notification: Strong component statistics for simulation (15):
 * Single equations (assignments): 13
 * Array equations: 0
 * Algorithm blocks: 0
 * Record equations: 0
 * When equations: 2
 * If-equations: 0
 * Equation systems (linear and non-linear blocks): 0
 * Torn equation systems: 0
 * Mixed (continuous/discrete) equation systems: 0
Notification: Performance of Backend phase and start with SimCode phase: time 0.0001289/0.6623, allocations: 103.2 kB / 0.7392 GB, free: 15.73 MB / 0.5606 GB
Notification: Performance of simCode: created initialization part: time 0.000846/0.6631, allocations: 343.9 kB / 0.7395 GB, free: 15.39 MB / 0.5606 GB
Notification: Performance of simCode: created event and clocks part: time 2.876e-06/0.6631, allocations: 0 / 0.7395 GB, free: 15.39 MB / 0.5606 GB
Notification: Performance of simCode: created simulation system equations: time 0.0002762/0.6634, allocations: 116.1 kB / 0.7396 GB, free: 15.28 MB / 0.5606 GB
Notification: Performance of simCode: created of all other equations (e.g. parameter, nominal, assert, etc): time 0.0003916/0.6638, allocations: 53.39 kB / 0.7397 GB, free: 15.23 MB / 0.5606 GB
Notification: Performance of simCode: created linear, non-linear and system jacobian parts: time 0.0009836/0.6648, allocations: 0.5599 MB / 0.7402 GB, free: 14.64 MB / 0.5606 GB
Notification: Performance of simCode: some other stuff during SimCode phase: time 0.0003726/0.6652, allocations: 0.7602 MB / 0.741 GB, free: 13.86 MB / 0.5606 GB
Notification: Performance of simCode: alias equations: time 0.000182/0.6654, allocations: 38.95 kB / 0.741 GB, free: 13.82 MB / 0.5606 GB
Notification: Performance of simCode: all other stuff during SimCode phase: time 8.227e-05/0.6655, allocations: 27.44 kB / 0.741 GB, free: 13.79 MB / 0.5606 GB
Notification: Performance of SimCode: time 2.71e-07/0.6655, allocations: 0 / 0.741 GB, free: 13.79 MB / 0.5606 GB
Notification: Performance of Templates: time 0.006296/0.6718, allocations: 2.741 MB / 0.7437 GB, free: 11.12 MB / 0.5606 GB
make -j1 -f Buildings_maint.7.0.x_Buildings.Controls.OBC.ASHRAE.G36_PR1.AHUs.SingleZone.VAV.Validation.CoolingCoil.makefile
Environment - environmentSimulation:
(rm -f Buildings_maint.7.0.x_Buildings.Controls.OBC.ASHRAE.G36_PR1.AHUs.SingleZone.VAV.Validation.CoolingCoil.pipe ; mkfifo Buildings_maint.7.0.x_Buildings.Controls.OBC.ASHRAE.G36_PR1.AHUs.SingleZone.VAV.Validation.CoolingCoil.pipe ; head -c 1048576 < Buildings_maint.7.0.x_Buildings.Controls.OBC.ASHRAE.G36_PR1.AHUs.SingleZone.VAV.Validation.CoolingCoil.pipe >> ../files/Buildings_maint.7.0.x_Buildings.Controls.OBC.ASHRAE.G36_PR1.AHUs.SingleZone.VAV.Validation.CoolingCoil.sim & ./Buildings_maint.7.0.x_Buildings.Controls.OBC.ASHRAE.G36_PR1.AHUs.SingleZone.VAV.Validation.CoolingCoil  -abortSlowSimulation -alarm=480 -lv LOG_STATS > Buildings_maint.7.0.x_Buildings.Controls.OBC.ASHRAE.G36_PR1.AHUs.SingleZone.VAV.Validation.CoolingCoil.pipe 2>&1)
Environment - environmentSimulation: