R1820

Summary

A Gate cannot cover a Lifeline.

Details

A Gate can only belong to an Interaction or an InteractionUse.

Tips

A PartDecomposition , which inherits InteractionUse, i_s represented in a Sequence Diagram by a Lifeline. This may be a cause of confusion because the Lifeline will visually be covered by Gates while these Gates really belong to the PartDecomposition that decompose the Lifeline_.