More use cases

RF2 tables shown here are on the format <source> <type> <destination>

Anatomy

Stated definitions and GCIs:

|part of| = |nose|, |laterality| = |left|
===
|all or part of| = |left half of nose|

|left half of nose|
===
|lateral half o nose|: |laterality| = |left|

|lateral half of nose|
===
|body structure|: |lateral half of| = |nose|
<<<
|lateral half of PAE|

RF2 (* classified):

|lateral half of nose| |isa| |body structure|
|lateral half of nose| |lateral half of| |nose|

The last line (*) is inferred from the GCI.

Disjunctive components in observables

GCIs could be one EL2-way of addressing disjunctive components in observables. Example from LOINC 53150-9

Single entity component observables are fully defined. Disjunctive components, i.e. where the component could be either or all of the entities listed, are primitives were the component is the least common subsumer and additional axioms state the superclass relationship to the single entity component observables.

Stated definitions and GCIs

|Alanine [Moles/volume] in Dried blood spot|
===
|Observable|:
|property type| = |substance concentration|,
|component| = |alanine|,
...

|Alanine+Beta Alanine+Sarcosine [Moles/volume] in Dried blood spot|
<<<
|Observable|:
|property type| = |substance concentration|,
|component| = |amino acid|, // actually amino acid and derivatives...
...
>>>
|Alanine [Moles/volume] in Dried blood spot|
>>>
|Beta Alanine [Moles/volume] in Dried blood spot|
>>>
|Sarcosine [Moles/volume] in Dried blood spot|

RF2:

|Alanine [Moles/volume] in Dried blood spot| |isa| |Observable|
|Alanine [Moles/volume] in Dried blood spot| |property type| |substance concentration|
|Alanine [Moles/volume] in Dried blood spot| |component| |alanine|
...
|Alanine [Moles/volume] in Dried blood spot| |isa| |Alanine+Beta Alanine+Sarcosine [Moles/volume] in Dried blood spot|
...

|Beta Alanine [Moles/volume] in Dried blood spot| |isa| |Alanine+Beta Alanine+Sarcosine [Moles/volume] in Dried blood spot|
...

|Sarcosine [Moles/volume] in Dried blood spot| |isa| |Alanine+Beta Alanine+Sarcosine [Moles/volume] in Dried blood spot|
...

|Alanine+Beta Alanine+Sarcosine [Moles/volume] in Dried blood spot| |isa| |Observable|
|Alanine+Beta Alanine+Sarcosine [Moles/volume] in Dried blood spot| |property type| |substance concentration|
...

Note that sufficient criteria are represented as additional isa:s on the subsumee.

A similar use case is described here and here.

Conclusion

While looking for GCI use cases among existing development projects two different kinds were found: (1) stating additional implications (also necessarily...) and (2) representing disjunction. In both cases the result (or non-result) of classification can be represented in the RF2 relationship table but, as explained by @michael lawley here, the stated form cannot. The possibility of representing the classification output in RF2 implies that there is no impact on ECL queryability as it is today.