# 5. Analysis of feed forward loops¶

**Design principles**

The C1-FFL with AND logic has an on-delay, but no off-delay.

The C1-FFL with OR logic has an off-delay, but no on-delay.

The C1-FFL with both AND and OR logic can filter out short input impulses.

The I1-FFL with AND logic is a pulse generator and also speeds response compared to an unregulated circuit.

**Concept**

When multiple factors regulate a single gene, we need to specify the logic of the regulation, usually OR or AND.

```
[1]:
```

```
import numpy as np
import scipy.integrate
import biocircuits
import bokeh.io
import bokeh.plotting
import colorcet
import panel as pn
bokeh.io.output_notebook()
pn.extension()
colors = colorcet.b_glasbey_category10
```