This is a vademecum for the FEEL expression language from the DMN specification, as also implemented by the Drools DMN open source engine.

This is not intented as an exahustive documentation of the DMN capabilities of Drools; this is intended as a handy a pocket reference for FEEL usage, a FEEL pocket guide, a FEEL reference, a FEEL quick reference, a FEEL cheatsheet,
a FEEL handbook.

Looking for a gentle introduction to the DMN standard? We have just the right crash course on DMN, freely available for you at: learn-dmn-in-15-minutes.com.

You can refer to the complete Drools DMN Engine documentation on the main Drools website here.

https://www.drools.org/learn/dmn.html