Removed logical definition from ice

Previously this was auto-classifying 'charcoal', 'dust', etc under ice
as the logical definition said: any environmental material that is frozen
or solid is a ice.

The logical definition was also much weaker than the text definition
which included a necessary qualifier about gravitational forces

While discussion may continue about the precise definition of ice (see tickets),
for now we can simply manually classify the obvious common-sense children (water ice,
methane ice)

Fixes #990
Fixes #955
Fixes #782

src/envo/envo-edit.owl

@@ -28786,10 +28786,10 @@ SubClassOf(<http://purl.obolibrary.org/obo/ENVO_01001124> <http://purl.obolibrar
 # Class: <http://purl.obolibrary.org/obo/ENVO_01001125> (ice)
 
 AnnotationAssertion(<http://purl.obolibrary.org/obo/IAO_0000115> <http://purl.obolibrary.org/obo/ENVO_01001125> "An ice is an environmental material which is either frozen or which is maintained in a solid state by gravitational forces or pressure.")
-AnnotationAssertion(rdfs:comment <http://purl.obolibrary.org/obo/ENVO_01001125> "This class is defined logically - any material that is frozen is considered a subclass. Note that ice may be formed at very high temperatures, due to gravitational effects and/or pressure.")
+AnnotationAssertion(rdfs:comment <http://purl.obolibrary.org/obo/ENVO_01001125> "Note that ice may be formed at very high temperatures, due to gravitational effects and/or pressure.")
 AnnotationAssertion(rdfs:label <http://purl.obolibrary.org/obo/ENVO_01001125> "ice"@en)
-EquivalentClasses(<http://purl.obolibrary.org/obo/ENVO_01001125> ObjectIntersectionOf(<http://purl.obolibrary.org/obo/ENVO_00010483> ObjectSomeValuesFrom(<http://purl.obolibrary.org/obo/RO_0000086> ObjectUnionOf(<http://purl.obolibrary.org/obo/PATO_0001546> <http://purl.obolibrary.org/obo/PATO_0001985>))))
 SubClassOf(<http://purl.obolibrary.org/obo/ENVO_01001125> <http://purl.obolibrary.org/obo/ENVO_00010483>)
+SubClassOf(Annotation(rdfs:seeAlso "https://github.com/EnvironmentOntology/envo/issues/900"^^xsd:anyURI) <http://purl.obolibrary.org/obo/ENVO_01001125> ObjectSomeValuesFrom(<http://purl.obolibrary.org/obo/RO_0000086> ObjectUnionOf(<http://purl.obolibrary.org/obo/PATO_0001546> <http://purl.obolibrary.org/obo/PATO_0001985>)))
 
 # Class: <http://purl.obolibrary.org/obo/ENVO_01001126> (astrogeological ice)