## IFPDOn

`IFPDOn[exp_, q1, q2, ...]` changes from `FeynAmpDenominator[...]` representation to the `IFPD` one (Inverse Feynman Propagator Denominator). I.e., `FeynAmpDenominator[PropagatorDenominator[a,b]]` is replaced by `1/IFPD[a,b]` and the `q1, q2, ...` are the integration momenta.

### See also

[Overview](Extra/FeynCalc.md), [IFPD](IFPD.md), [IFPDOff](IFPDOff.md).

### Examples