Check whether `transformation` should be an equivalent class

[l-emele]

Description of the issue

transformation is defined as: A transformation is a process that transforms one or more inputs into at least one output.

process as a lot of subclasses. Some of them are candidates for being subclasses of transformation

Ideas of solution

Potentially make transformation an equivalent class

EDIT: The axiom could be: transformation EquivalentTo: process and ('has input' some entity) and ('has output' some entity'). This would differentiate from processes, which only have participants (e.g. wind which has participant air, but no in- our outputs).

Workflow checklist

• [ ] I discussed the issue with someone else than me before working on a solution
• [ ] I already read the latest version of the workflow for this repository
• [ ] The goal of this ontology is clear to me

I am aware that

• [ ] every entry in the ontology should have a definition
• [ ] classes should arise from concepts rather than from words

[stap-m]

The axiom you propose fits well to the defining axiom of material transformation which is a specific transformation. transformation and ('has physical input' some 'material entity') and ('has physical output' some 'material entity').

It might cause problems with energy transformation though, when there are processes that have energy inputs / outputs defined, but not physical inputs / outputs, e.g. wind energy transformation.

[l-emele]

Sorry, I meant transformation EquivalentTo: process and ('has input' some entity) and ('has output' some entity'), I changed it above.

[stap-m]

I am ok with this idea. Maybe this one can be solved quickly and can help to proceed with #1527.

It would require some adjustment in the axioms of the subclasses, though:

• chemical reaction has no inputs and outputs defined. If we added has input some material entity and has output some material entity, it would be the same as material transformation. Probably, it should be a subclass of the latter. We should discuss this later in a separate issue, in my opinion.
• radiation should become a subclass of process instead, I guess.

energy transfer an heat transfer should be treated in the discussion in #1527.