| Fire modelling | Usually, modelling the spatial spread of fire across a landscape |
| Fixed-membership submodel | A submodel with a fixed number of instances (e.g. a submodel representing a fixed number of spatial grid squares or age-classes) |
| Food web | The pattern of who-eats-whom in ecosystems |
| Forest dynamics | Typically, the changes in number of trees |
| Fractals | Self-similarity at different levels of detail |
| function last | The Simile function last(X), returning the value of element X from the previous time step |
| function prev | The Simile function prev(N), which returns the value of the same variable N time units ago |