SystemModelEventually
SystemModelEventually[t,texpr]
is True if the temporal expression texpr eventually becomes True.
SystemModelEventually[t,cond,texpr]
is True if texpr eventually becomes True in an interval where the temporal expression cond is True.
Details
- SystemModelEventually is typically used to specify requirements that must be satisfied at least once and may be used to establish if the system ever accomplishes a relevant task or reaches a problematic state.
- SystemModelEventually[t,texpr[t]] is True if texpr[t] is True for a validation time
. - SystemModelEventually[t,texpr[t]] is False if texpr[t] is False for all validation times
. - The times
and 
are given by the simulation interval of the system. - The condition cond is often used to select a subset of the validation interval, as in
. - SystemModelEventually[t,cond[t],texpr[t]] is True if texpr[t] is True for some t where cond[t] is True.
- SystemModelEventually or SystemModelAlways is used as the outer wrapper of a temporal specification in functions like SystemModelValidate.
Examples
open all close allBasic Examples (1)
Validate the requirement, "The aircraft must reach an operational service life of 150 flight cycles or 800 flight hours, whichever is more stringent.":
model = ConnectSystemModelComponents[...]Use SystemModelEventually to validate a condition that must be satisfied at least once:
SystemModelValidate[model, SystemModelEventually[t, "FlightCycles.y"[t] ≥ 150 || "FlightTime.y"[t] ≥ 800 * 3600]]Scope (4)
Basic Uses (2)
Validate requirements in a model of a pendulum:
model = CreateSystemModel["MyPendulum", {θ'[t] == ω[t], ω'[t] == -θ[t], right[t] == (θ[t] ≥ 0), θ[0] == 1}, t, {right∈ Booleans}, <|"SimulationSettings" -> <|"StopTime" -> 10|>|>];
SystemModelPlot[model, {θ, right}]Validate the requirement, "The angle must be greater than or equal to 0.5 at some time.":
SystemModelValidate[model, SystemModelEventually[t, 0.5 ≤ θ[t]]]Validate the requirement, "The angle must be to the right of the central position at some time.":
SystemModelValidate[model, SystemModelEventually[t, right[t]]]Validate the requirement, "The angle must be greater than or equal to 1.5 at some time.":
smv = SystemModelValidate[model, SystemModelEventually[t, 1.5 ≤ θ[t]]]smv["FailurePlot", 1]Validate requirements in a model of an RC circuit:
model = CreateSystemModel["RCCircuit", {v[t] + r c v'[t] == 0, v[0] == v0, v0 == 1, r == 10, c == 1 / 5}, t, <|"SimulationSettings" -> <|"StopTime" -> 10|>|>];
SystemModelPlot[model, {v, v0 / E}]Validate a requirement with variables evaluated at specific times:
SystemModelValidate[model, SystemModelEventually[t, t < 2, v[r c] < v[t]]]Validate a requirement with variables evaluated at different times:
SystemModelValidate[model, SystemModelEventually[t, v[t + r c] ≤ v[t]]]Condition (2)
Validate requirements for times satisfying conditions in a model of a pendulum:
model = CreateSystemModel["MyPendulum", {θ'[t] == ω[t], ω'[t] == -θ[t], right[t] == (θ[t] ≥ 0), θ[0] == 1}, t, {right∈ Booleans}, <|"SimulationSettings" -> <|"StopTime" -> 10|>|>];
SystemModelPlot[model, {θ, right}]Validate the requirement, "The angle must be greater than or equal to 0.5 at some time less than or equal to 
.":
SystemModelValidate[model, SystemModelEventually[t, t ≤ π / 2, 0.5 ≤ θ[t]]]Validate the requirement, "The angle must be greater than or equal to 0.5 at some time less than or equal to 
or a time between 
and 
.":
SystemModelValidate[model, SystemModelEventually[t, Or[t ≤ π / 4, 7π / 4 ≤ t ≤ 9π / 4], 0.5 ≤ θ[t]]]Validate the requirement with a condition that uses intervals instead:
SystemModelValidate[model, SystemModelEventually[t, {t}∈Interval[{0, π / 4}, {7π / 4, 9π / 4}], 0.5 ≤ θ[t]]]Validate the requirement, "The angle must be greater than or equal to 0.5 and the angular velocity must be negative for some time between 
and 
.":
smv = SystemModelValidate[model, SystemModelEventually[t, π ≤ t ≤ 2π, And[0.5 ≤ θ[t], ω[t] < 0]]]smv["FailurePlot", 1]Validate a requirement with a parameter-dependent condition:
model = CreateSystemModel["RCCircuit", {v[t] + r c v'[t] == 0, v[0] == v0, v0 == 1, r == 10, c == 1 / 5}, t, <|"SimulationSettings" -> <|"StopTime" -> 10|>|>];
SystemModelPlot[model, {v, v0 / E}]Validate a requirement in a model of an RC circuit:
SystemModelValidate[model, SystemModelEventually[t, t < r c, v[r c] < v[t]]]Applications (1)
Start with a simple model of an electrical vehicle following the US EPA Highway Fuel Economy Driving Schedule (HWFET):
model = \!\(\*GraphicsBox[«8»]\);Validate the requirement, "The vehicle must reach a velocity of 15 m/s within the first 22 seconds.":
SystemModelValidate[model, SystemModelEventually[t, t ≤ 22, 15 ≤ "mass.v"]]Validate the stricter requirement, "The vehicle must reach a velocity of 15 m/s within the first 20 seconds.":
SystemModelValidate[model, SystemModelEventually[t, t ≤ 20, 15 ≤ "mass.v"]]Plot the velocity with the bound:
SystemModelPlot[model, {"mass.v", 15}, 25, ...]The car reaches the desired velocity in 21.16 seconds:
FindRoot[SystemModelSimulate[model, 25]["mass.v", t] == 15, {t, 21}]Related Links
Wolfram System Modeler DocumentationText
Wolfram Research (2025), SystemModelEventually, Wolfram Language function, https://reference.wolfram.com/language/ref/SystemModelEventually.html.
CMS
Wolfram Language. 2025. "SystemModelEventually." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/SystemModelEventually.html.
APA
Wolfram Language. (2025). SystemModelEventually. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/SystemModelEventually.html