Running: ./testmodel.py --libraries=/home/hudson/saved_omc/libraries/.openmodelica/libraries/ --ompython_omhome=/usr Buildings_maint.7.0.x_Buildings.Fluid.HeatExchangers.ActiveBeams.BaseClasses.Examples.Convector.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.Fluid.HeatExchangers.ActiveBeams.BaseClasses.Examples.Convector,tolerance=1e-06,outputFormat="empty",numberOfIntervals=5000,variableFilter="",fileNamePrefix="Buildings_maint.7.0.x_Buildings.Fluid.HeatExchangers.ActiveBeams.BaseClasses.Examples.Convector")
translateModel(Buildings.Fluid.HeatExchangers.ActiveBeams.BaseClasses.Examples.Convector,tolerance=1e-06,outputFormat="empty",numberOfIntervals=5000,variableFilter="",fileNamePrefix="Buildings_maint.7.0.x_Buildings.Fluid.HeatExchangers.ActiveBeams.BaseClasses.Examples.Convector")
Notification: Performance of loadFile(/home/hudson/saved_omc/libraries/.openmodelica/libraries/ModelicaServices 4.0.0+maint.om/package.mo): time 0.0007545/0.0007545, allocations: 91.84 kB / 15.36 MB, free: 0.7383 MB / 14.72 MB
Notification: Performance of loadFile(/home/hudson/saved_omc/libraries/.openmodelica/libraries/Complex 4.0.0+maint.om/package.mo): time 0.004954/0.004954, allocations: 173.9 kB / 16.27 MB, free: 6.676 MB / 14.72 MB
Notification: Performance of loadFile(/home/hudson/saved_omc/libraries/.openmodelica/libraries/Modelica 3.2.3+maint.om/package.mo): time 1.435/1.435, allocations: 205.4 MB / 222.4 MB, free: 5.562 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 1.554/1.554, allocations: 252 MB / 0.5105 GB, free: 4.695 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 0.0005677/0.0005678, allocations: 16 kB / 0.6249 GB, free: 0.7383 MB / 0.5137 GB
Notification: Performance of FrontEnd - Absyn->SCode: time 0.4683/0.4689, allocations: 106.4 MB / 0.7287 GB, free: 11.39 MB / 0.545 GB
Notification: Performance of NFInst.instantiate(Buildings.Fluid.HeatExchangers.ActiveBeams.BaseClasses.Examples.Convector): time 0.04405/0.513, allocations: 40.88 MB / 0.7687 GB, free: 2.355 MB / 0.5762 GB
Notification: Performance of NFInst.instExpressions: time 0.01327/0.5263, allocations: 8.792 MB / 0.7773 GB, free: 9.551 MB / 0.5919 GB
Notification: Performance of NFInst.updateImplicitVariability: time 0.001953/0.5283, allocations: 35.75 kB / 0.7773 GB, free: 9.516 MB / 0.5919 GB
Notification: Performance of NFTyping.typeComponents: time 0.002126/0.5305, allocations: 485.4 kB / 0.7777 GB, free: 9.039 MB / 0.5919 GB
Notification: Performance of NFTyping.typeBindings: time 0.004737/0.5352, allocations: 1.174 MB / 0.7789 GB, free: 7.859 MB / 0.5919 GB
Notification: Performance of NFTyping.typeClassSections: time 0.003578/0.5388, allocations: 1.032 MB / 0.7799 GB, free: 6.836 MB / 0.5919 GB
Notification: Performance of NFFlatten.flatten: time 0.004673/0.5435, allocations: 3.336 MB / 0.7832 GB, free: 3.488 MB / 0.5919 GB
Notification: Performance of NFFlatten.resolveConnections: time 0.001556/0.5451, allocations: 0.7456 MB / 0.7839 GB, free: 2.723 MB / 0.5919 GB
Notification: Performance of NFEvalConstants.evaluate: time 0.002121/0.5472, allocations: 0.8281 MB / 0.7847 GB, free: 1.891 MB / 0.5919 GB
Notification: Performance of NFSimplifyModel.simplify: time 0.001479/0.5487, allocations: 0.6959 MB / 0.7854 GB, free: 1.191 MB / 0.5919 GB
Notification: Performance of NFPackage.collectConstants: time 0.0002451/0.549, allocations: 39.94 kB / 0.7854 GB, free: 1.152 MB / 0.5919 GB
Notification: Performance of NFFlatten.collectFunctions: time 0.002545/0.5515, allocations: 1.057 MB / 0.7864 GB, free: 96 kB / 0.5919 GB
Notification: Performance of NFScalarize.scalarize: time 0.0004138/0.552, allocations: 255 kB / 0.7867 GB, free: 15.84 MB / 0.6075 GB
Notification: Performance of NFVerifyModel.verify: time 0.001009/0.553, allocations: 0.5612 MB / 0.7872 GB, free: 15.27 MB / 0.6075 GB
Notification: Performance of NFConvertDAE.convert: time 0.003545/0.5566, allocations: 2.22 MB / 0.7894 GB, free: 13.05 MB / 0.6075 GB
Notification: Performance of FrontEnd - DAE generated: time 4.939e-06/0.5566, allocations: 0 / 0.7894 GB, free: 13.05 MB / 0.6075 GB
Notification: Performance of FrontEnd: time 2.134e-06/0.5566, allocations: 0 / 0.7894 GB, free: 13.05 MB / 0.6075 GB
Notification: Performance of Transformations before backend: time 6.197e-05/0.5567, allocations: 0 / 0.7894 GB, free: 13.05 MB / 0.6075 GB
Notification: Model statistics after passing the front-end and creating the data structures used by the back-end:
 * Number of equations: 157
 * Number of variables: 157
Notification: Performance of Generate backend data structure: time 0.003018/0.5597, allocations: 1.518 MB / 0.7909 GB, free: 11.43 MB / 0.6075 GB
Notification: Performance of prepare preOptimizeDAE: time 4.751e-05/0.5597, allocations: 12.03 kB / 0.7909 GB, free: 11.42 MB / 0.6075 GB
Notification: Performance of preOpt normalInlineFunction (simulation): time 0.000439/0.5602, allocations: 131.4 kB / 0.791 GB, free: 11.29 MB / 0.6075 GB
Notification: Performance of preOpt evaluateParameters (simulation): time 0.002137/0.5623, allocations: 1.062 MB / 0.7921 GB, free: 10.19 MB / 0.6075 GB
Notification: Performance of preOpt simplifyIfEquations (simulation): time 5.114e-05/0.5624, allocations: 49.31 kB / 0.7921 GB, free: 10.14 MB / 0.6075 GB
Notification: Performance of preOpt expandDerOperator (simulation): time 0.0001529/0.5626, allocations: 67.91 kB / 0.7922 GB, free: 10.07 MB / 0.6075 GB
Notification: Performance of preOpt clockPartitioning (simulation): time 0.001565/0.5641, allocations: 0.8098 MB / 0.793 GB, free: 9.238 MB / 0.6075 GB
Notification: Performance of preOpt findStateOrder (simulation): time 2.65e-05/0.5642, allocations: 7.922 kB / 0.793 GB, free: 9.23 MB / 0.6075 GB
Notification: Performance of preOpt replaceEdgeChange (simulation): time 7.387e-05/0.5643, allocations: 28 kB / 0.793 GB, free: 9.203 MB / 0.6075 GB
Notification: Performance of preOpt inlineArrayEqn (simulation): time 3.199e-05/0.5643, allocations: 19.94 kB / 0.793 GB, free: 9.184 MB / 0.6075 GB
Notification: Performance of preOpt removeEqualRHS (simulation): time 0.001265/0.5656, allocations: 0.6219 MB / 0.7936 GB, free: 8.562 MB / 0.6075 GB
Warning: The model contains alias variables with redundant start and/or conflicting nominal values. It is recommended to resolve the conflicts, because otherwise the system could be hard to solve. To print the conflicting alias sets and the chosen candidates please use -d=aliasConflicts.
Notification: Performance of preOpt removeSimpleEquations (simulation): time 0.00468/0.5703, allocations: 3.212 MB / 0.7968 GB, free: 5.184 MB / 0.6075 GB
Notification: Performance of preOpt comSubExp (simulation): time 0.0008397/0.5711, allocations: 465.9 kB / 0.7972 GB, free: 4.723 MB / 0.6075 GB
Notification: Performance of preOpt resolveLoops (simulation): time 0.0004873/0.5716, allocations: 320.7 kB / 0.7975 GB, free: 4.406 MB / 0.6075 GB
Notification: Performance of preOpt evalFunc (simulation): time 0.0008454/0.5725, allocations: 0.7792 MB / 0.7983 GB, free: 3.461 MB / 0.6075 GB
Notification: Performance of preOpt encapsulateWhenConditions (simulation): time 2.853e-05/0.5725, allocations: 34.56 kB / 0.7983 GB, free: 3.418 MB / 0.6075 GB
Notification: Performance of pre-optimization done (n=38): time 2.855e-06/0.5725, allocations: 0 / 0.7983 GB, free: 3.418 MB / 0.6075 GB
Notification: Performance of matching and sorting (n=38): time 0.001726/0.5743, allocations: 1.013 MB / 0.7993 GB, free: 2.379 MB / 0.6075 GB
Notification: Performance of inlineWhenForInitialization (initialization): time 8.113e-05/0.5744, allocations: 148.4 kB / 0.7994 GB, free: 2.203 MB / 0.6075 GB
Notification: Performance of selectInitializationVariablesDAE (initialization): time 0.001683/0.5761, allocations: 1.075 MB / 0.8005 GB, free: 1.109 MB / 0.6075 GB
Notification: Performance of collectPreVariables (initialization): time 5.945e-05/0.5761, allocations: 33.7 kB / 0.8005 GB, free: 1.07 MB / 0.6075 GB
Notification: Performance of collectInitialEqns (initialization): time 0.0003929/0.5765, allocations: 468.5 kB / 0.801 GB, free: 0.6094 MB / 0.6075 GB
Notification: Performance of collectInitialBindings (initialization): time 0.0001275/0.5767, allocations: 130.1 kB / 0.8011 GB, free: 492 kB / 0.6075 GB
Notification: Performance of simplifyInitialFunctions (initialization): time 7.937e-05/0.5767, allocations: 57.69 kB / 0.8011 GB, free: 428 kB / 0.6075 GB
Notification: Performance of setup shared object (initialization): time 0.0001123/0.5769, allocations: 326 kB / 0.8015 GB, free: 96 kB / 0.6075 GB
Notification: Performance of preBalanceInitialSystem (initialization): time 0.0005339/0.5774, allocations: 348.8 kB / 0.8018 GB, free: 15.75 MB / 0.6231 GB
Notification: Performance of partitionIndependentBlocks (initialization): time 0.0006253/0.578, allocations: 458.8 kB / 0.8022 GB, free: 15.27 MB / 0.6231 GB
Notification: Performance of analyzeInitialSystem (initialization): time 0.001232/0.5793, allocations: 0.9834 MB / 0.8032 GB, free: 14.21 MB / 0.6231 GB
Notification: Performance of solveInitialSystemEqSystem (initialization): time 3.406e-06/0.5793, allocations: 0 / 0.8032 GB, free: 14.21 MB / 0.6231 GB
Notification: Performance of matching and sorting (n=62) (initialization): time 0.001563/0.5809, allocations: 1.115 MB / 0.8043 GB, free: 13.06 MB / 0.6231 GB
Notification: Performance of prepare postOptimizeDAE: time 0.0001837/0.5811, allocations: 323.4 kB / 0.8046 GB, free: 12.67 MB / 0.6231 GB
Notification: Performance of postOpt simplifyComplexFunction (initialization): time 7.945e-06/0.5811, allocations: 0 / 0.8046 GB, free: 12.67 MB / 0.6231 GB
Notification: Performance of postOpt tearingSystem (initialization): time 1.777e-05/0.5811, allocations: 11.94 kB / 0.8046 GB, free: 12.66 MB / 0.6231 GB
Notification: Performance of postOpt solveSimpleEquations (initialization): time 0.0003485/0.5815, allocations: 87.89 kB / 0.8047 GB, free: 12.57 MB / 0.6231 GB
Notification: Performance of postOpt calculateStrongComponentJacobians (initialization): time 1.101e-05/0.5815, allocations: 4 kB / 0.8047 GB, free: 12.57 MB / 0.6231 GB
Notification: Performance of postOpt simplifyAllExpressions (initialization): time 0.0007124/0.5822, allocations: 111.2 kB / 0.8048 GB, free: 12.46 MB / 0.6231 GB
Notification: Performance of postOpt collapseArrayExpressions (initialization): time 7.056e-05/0.5823, allocations: 31.92 kB / 0.8048 GB, free: 12.43 MB / 0.6231 GB
Notification: Performance of prepare postOptimizeDAE: time 9.959e-06/0.5823, allocations: 4 kB / 0.8048 GB, free: 12.43 MB / 0.6231 GB
Notification: Performance of postOpt replaceHomotopyWithSimplified (initialization): time 0.001469/0.5838, allocations: 1.112 MB / 0.8059 GB, free: 11.28 MB / 0.6231 GB
Notification: Performance of postOpt simplifyComplexFunction (initialization): time 3.907e-06/0.5838, allocations: 3.938 kB / 0.8059 GB, free: 11.28 MB / 0.6231 GB
Notification: Performance of postOpt tearingSystem (initialization): time 5.129e-06/0.5838, allocations: 4 kB / 0.8059 GB, free: 11.27 MB / 0.6231 GB
Notification: Performance of postOpt solveSimpleEquations (initialization): time 0.0003329/0.5842, allocations: 96.05 kB / 0.806 GB, free: 11.18 MB / 0.6231 GB
Notification: Performance of postOpt calculateStrongComponentJacobians (initialization): time 8.175e-06/0.5842, allocations: 4 kB / 0.806 GB, free: 11.18 MB / 0.6231 GB
Notification: Performance of postOpt simplifyAllExpressions (initialization): time 0.0007098/0.5849, allocations: 105.9 kB / 0.8061 GB, free: 11.07 MB / 0.6231 GB
Notification: Performance of postOpt collapseArrayExpressions (initialization): time 5.353e-05/0.5849, allocations: 23.98 kB / 0.8061 GB, free: 11.05 MB / 0.6231 GB
Notification: Model statistics after passing the back-end for initialization:
 * Number of independent subsystems: 8
 * Number of states: 0 ()
 * Number of discrete variables: 3 (con.mod.airFlo_mod.i,con.mod.watFlo_mod.i,con.mod.temDif_mod.i)
 * Number of discrete states: 0 ()
 * Number of clocked states: 0 ()
 * Top-level inputs: 0
Notification: Strong component statistics for initialization (53):
 * Single equations (assignments): 47
 * Array equations: 0
 * Algorithm blocks: 6
 * Record equations: 0
 * When equations: 0
 * If-equations: 0
 * Equation systems (not torn): 0
 * Torn equation systems: 0
 * Mixed (continuous/discrete) equation systems: 0
Notification: Performance of prepare postOptimizeDAE: time 0.0005703/0.5855, allocations: 474.1 kB / 0.8066 GB, free: 10.56 MB / 0.6231 GB
Notification: Performance of postOpt lateInlineFunction (simulation): time 0.000184/0.5857, allocations: 106.7 kB / 0.8067 GB, free: 10.45 MB / 0.6231 GB
Notification: Performance of postOpt wrapFunctionCalls (simulation): time 0.001539/0.5873, allocations: 0.925 MB / 0.8076 GB, free: 9.508 MB / 0.6231 GB
Notification: Performance of postOpt inlineArrayEqn (simulation): time 1.332e-05/0.5873, allocations: 7.984 kB / 0.8076 GB, free: 9.5 MB / 0.6231 GB
Notification: Performance of postOpt constantLinearSystem (simulation): time 5.12e-06/0.5873, allocations: 4 kB / 0.8076 GB, free: 9.496 MB / 0.6231 GB
Notification: Performance of postOpt simplifysemiLinear (simulation): time 0.001127/0.5884, allocations: 0.9832 MB / 0.8086 GB, free: 8.426 MB / 0.6231 GB
Notification: Performance of postOpt removeSimpleEquations (simulation): time 0.003241/0.5917, allocations: 2.129 MB / 0.8106 GB, free: 6.176 MB / 0.6231 GB
Notification: Performance of postOpt simplifyComplexFunction (simulation): time 8.295e-06/0.5917, allocations: 8.062 kB / 0.8107 GB, free: 6.168 MB / 0.6231 GB
Notification: Performance of postOpt solveSimpleEquations (simulation): time 0.0002817/0.592, allocations: 63.91 kB / 0.8107 GB, free: 6.105 MB / 0.6231 GB
Notification: Performance of postOpt tearingSystem (simulation): time 7.394e-06/0.592, allocations: 8.281 kB / 0.8107 GB, free: 6.098 MB / 0.6231 GB
Notification: Performance of postOpt inputDerivativesUsed (simulation): time 3.993e-05/0.5921, allocations: 15.98 kB / 0.8107 GB, free: 6.082 MB / 0.6231 GB
Notification: Performance of postOpt calculateStrongComponentJacobians (simulation): time 5.791e-06/0.5921, allocations: 7.938 kB / 0.8107 GB, free: 6.074 MB / 0.6231 GB
Notification: Performance of postOpt calculateStateSetsJacobians (simulation): time 2.635e-06/0.5921, allocations: 4 kB / 0.8107 GB, free: 6.07 MB / 0.6231 GB
Notification: Performance of postOpt symbolicJacobian (simulation): time 0.001908/0.594, allocations: 1.412 MB / 0.8121 GB, free: 4.594 MB / 0.6231 GB
Notification: Performance of postOpt removeConstants (simulation): time 0.0004977/0.5945, allocations: 291.5 kB / 0.8124 GB, free: 4.289 MB / 0.6231 GB
Notification: Performance of postOpt simplifyTimeIndepFuncCalls (simulation): time 0.0001797/0.5947, allocations: 15.98 kB / 0.8124 GB, free: 4.273 MB / 0.6231 GB
Notification: Performance of postOpt simplifyAllExpressions (simulation): time 0.0006179/0.5953, allocations: 63.86 kB / 0.8125 GB, free: 4.211 MB / 0.6231 GB
Notification: Performance of postOpt findZeroCrossings (simulation): time 0.0001336/0.5955, allocations: 43.89 kB / 0.8125 GB, free: 4.168 MB / 0.6231 GB
Notification: Performance of postOpt collapseArrayExpressions (simulation): time 5.209e-05/0.5955, allocations: 23.98 kB / 0.8125 GB, free: 4.145 MB / 0.6231 GB
Notification: Performance of sorting global known variables: time 0.001231/0.5968, allocations: 0.7767 MB / 0.8133 GB, free: 3.359 MB / 0.6231 GB
Notification: Performance of sort global known variables: time 1.41e-07/0.5968, allocations: 0 / 0.8133 GB, free: 3.359 MB / 0.6231 GB
Notification: Performance of remove unused functions: time 0.0016/0.5984, allocations: 0.5187 MB / 0.8138 GB, free: 2.84 MB / 0.6231 GB
Notification: Model statistics after passing the back-end for simulation:
 * Number of independent subsystems: 10
 * Number of states: 2 (con.hex.vol.dynBal.U,senTem.T)
 * Number of discrete variables: 3 (con.mod.temDif_mod.i,con.mod.watFlo_mod.i,con.mod.airFlo_mod.i)
 * Number of discrete states: 3 (con.mod.airFlo_mod.i,con.mod.watFlo_mod.i,con.mod.temDif_mod.i)
 * Number of clocked states: 0 ()
 * Top-level inputs: 0
Notification: Strong component statistics for simulation (38):
 * Single equations (assignments): 31
 * Array equations: 0
 * Algorithm blocks: 3
 * Record equations: 4
 * When equations: 0
 * If-equations: 0
 * Equation systems (not torn): 0
 * Torn equation systems: 0
 * Mixed (continuous/discrete) equation systems: 0
Notification: Performance of Backend phase and start with SimCode phase: time 0.0009902/0.5994, allocations: 391 kB / 0.8142 GB, free: 2.461 MB / 0.6231 GB
Notification: Performance of simCode: created initialization part: time 0.00252/0.6019, allocations: 1.954 MB / 0.8161 GB, free: 368 kB / 0.6231 GB
Notification: Performance of simCode: created event and clocks part: time 4.939e-06/0.6019, allocations: 0 / 0.8161 GB, free: 368 kB / 0.6231 GB
Notification: Performance of simCode: created simulation system equations: time 0.000737/0.6027, allocations: 0.5531 MB / 0.8166 GB, free: 15.77 MB / 0.6387 GB
Notification: Performance of simCode: created of all other equations (e.g. parameter, nominal, assert, etc): time 0.002992/0.6057, allocations: 0.526 MB / 0.8171 GB, free: 15.25 MB / 0.6387 GB
Notification: Performance of simCode: created linear, non-linear and system jacobian parts: time 0.003292/0.609, allocations: 2.276 MB / 0.8194 GB, free: 12.91 MB / 0.6387 GB
Notification: Performance of simCode: some other stuff during SimCode phase: time 0.0007521/0.6098, allocations: 1.076 MB / 0.8204 GB, free: 11.8 MB / 0.6387 GB
Notification: Performance of simCode: alias equations: time 0.0008551/0.6106, allocations: 211.2 kB / 0.8206 GB, free: 11.61 MB / 0.6387 GB
Notification: Performance of simCode: all other stuff during SimCode phase: time 0.0002222/0.6109, allocations: 79.42 kB / 0.8207 GB, free: 11.53 MB / 0.6387 GB
Notification: Performance of SimCode: time 1.232e-06/0.6109, allocations: 3.938 kB / 0.8207 GB, free: 11.52 MB / 0.6387 GB
Notification: Performance of Templates: time 0.04204/0.6529, allocations: 23.72 MB / 0.8439 GB, free: 4.133 MB / 0.6544 GB
make -j1 -f Buildings_maint.7.0.x_Buildings.Fluid.HeatExchangers.ActiveBeams.BaseClasses.Examples.Convector.makefile
Environment - environmentSimulation:
(rm -f Buildings_maint.7.0.x_Buildings.Fluid.HeatExchangers.ActiveBeams.BaseClasses.Examples.Convector.pipe ; mkfifo Buildings_maint.7.0.x_Buildings.Fluid.HeatExchangers.ActiveBeams.BaseClasses.Examples.Convector.pipe ; head -c 1048576 < Buildings_maint.7.0.x_Buildings.Fluid.HeatExchangers.ActiveBeams.BaseClasses.Examples.Convector.pipe >> ../files/Buildings_maint.7.0.x_Buildings.Fluid.HeatExchangers.ActiveBeams.BaseClasses.Examples.Convector.sim & ./Buildings_maint.7.0.x_Buildings.Fluid.HeatExchangers.ActiveBeams.BaseClasses.Examples.Convector  -abortSlowSimulation -alarm=480 -lv LOG_STATS > Buildings_maint.7.0.x_Buildings.Fluid.HeatExchangers.ActiveBeams.BaseClasses.Examples.Convector.pipe 2>&1)
Environment - environmentSimulation: