WOLFRAM SYSTEM MODELER
    GilpinGilpin population dynamics model  | 
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SystemModel["SystemDynamics.IntroductoryExamples.Gilpin"]

References:
Simulate the model across 5000 time units and plot the three populations:
  
 
You need to reduce the accuracy to 1e-10 in order for the simulation to run correctly.
| x1 | 
         Type: Real Description: Prey_1 population  | 
    
|---|---|
| x2 | 
         Type: Real Description: Prey_2 population  | 
    
| x3 | 
         Type: Real Description: Predator population  | 
    
| Source1 | 
         Type: Source Description: This is the (dummy) source model of System Dynamics  | 
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|---|---|---|
| Prey_1 | 
         Type: Level Description: General System Dynamics level  | 
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| Sink1 | 
         Type: Sink Description: This is the (dummy) sink model of System Dynamics  | 
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| Source2 | 
         Type: Source Description: This is the (dummy) source model of System Dynamics  | 
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| Prey_2 | 
         Type: Level Description: General System Dynamics level  | 
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| Sink2 | 
         Type: Sink Description: This is the (dummy) sink model of System Dynamics  | 
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| Death_1 | 
         Type: Rate_3 Description: Unrestricted additive rate element with three influencing variables  | 
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| Birth_2 | 
         Type: Rate_1 Description: Unrestricted rate element with one influencing variable  | 
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| Death_2 | 
         Type: Rate_3 Description: Unrestricted additive rate element with three influencing variables  | 
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| Prod_3_1 | 
         Type: Prod_3 Description: Product of three influencing factors  | 
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| k1 | 
         Type: Const Description: A constant factor  | 
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| Prod_3_2 | 
         Type: Prod_3 Description: Product of three influencing factors  | 
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| k2 | 
         Type: Const Description: A constant factor  | 
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| Prod_3_3 | 
         Type: Prod_3 Description: Product of three influencing factors  | 
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| k3 | 
         Type: Const Description: A constant factor  | 
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| Prod_3_4 | 
         Type: Prod_3 Description: Product of three influencing factors  | 
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| k4 | 
         Type: Const Description: A constant factor  | 
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| Predator | 
         Type: Level Description: General System Dynamics level  | 
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| Death_P | 
         Type: Rate_1 Description: Unrestricted rate element with one influencing variable  | 
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| Birth_P | 
         Type: Rate_2 Description: Unrestricted additive rate element with two influencing variables  | 
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| Source3 | 
         Type: Source Description: This is the (dummy) source model of System Dynamics  | 
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| Sink3 | 
         Type: Sink Description: This is the (dummy) sink model of System Dynamics  | 
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| Prod_3_5 | 
         Type: Prod_3 Description: Product of three influencing factors  | 
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| k5 | 
         Type: Const Description: A constant factor  | 
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| Prod_3_6 | 
         Type: Prod_3 Description: Product of three influencing factors  | 
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| k6 | 
         Type: Const Description: A constant factor  | 
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| Prod_3_7 | 
         Type: Prod_3 Description: Product of three influencing factors  | 
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| k7 | 
         Type: Const Description: A constant factor  | 
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| Prod_3_8 | 
         Type: Prod_3 Description: Product of three influencing factors  | 
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| k8 | 
         Type: Const Description: A constant factor  | 
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| Birth_1 | 
         Type: Rate_1 Description: Unrestricted rate element with one influencing variable  |