ECL Bug, Zero In-Group Cardinality Matches Nothing

[kaicode]

This bug affects ECL queries when requesting a set of concepts that have none of a particular attribute within an attribute group. The bug is that this type of ECL never matches any concepts, even when it should

For example:

< 387713003 |Surgical procedure| : { [0..0] << 363704007 |Procedure site| = * }

This should match about two thousand concepts but currently in Snowstorm it matches none.

Thank you to @LindaBird (Bellbird Informatics) for raising this.

[kaicode]

Update freshdesk ticket 49945