Create SSSOM file of obsolete and their replaced_by terms

Use the merged.owl mirror to create a sssom file of mappings from obsolete terms to the term they are replaced by. This file will be added to the Mapping Commons and used to rewire any mappings that are using the obsolete terms.

Obsolete terms have the annotation:

<owl:deprecated rdf:datatype="http://www.w3.org/2001/XMLSchema#boolean">true</owl:deprecated>

Depending on the ontology, the "replaced by" term (if there is one) is indicated in a few different ways:

• IAO_0100001 (term replaced by), with the replaced by term represented as either a CURIE or a URI.

  <owl:Class rdf:about="http://purl.obolibrary.org/obo/MONDO_0018726">
        <obo:IAO_0100001>MONDO:0003832</obo:IAO_0100001>
        <oboInOwl:id>MONDO:0018726</oboInOwl:id>
        <rdfs:label>obsolete immunodeficiency due to a complement cascade component deficiency</rdfs:label>
        <owl:deprecated rdf:datatype="http://www.w3.org/2001/XMLSchema#boolean">true</owl:deprecated>
    </owl:Class>

  Note: there can be more than one replace by term

  <owl:Class rdf:about="http://purl.obolibrary.org/obo/HP_0000535">
        <obo:IAO_0100001 rdf:resource="http://purl.obolibrary.org/obo/HP_0045074"/>
        <obo:IAO_0100001 rdf:resource="http://purl.obolibrary.org/obo/HP_0045075"/>
        <oboInOwl:id>HP:0000535</oboInOwl:id>
        <rdfs:label>obsolete Sparse and thin eyebrow</rdfs:label>
        <owl:deprecated rdf:datatype="http://www.w3.org/2001/XMLSchema#boolean">true</owl:deprecated>
    </owl:Class>

• oboInOwl:consider

  <owl:Class rdf:about="http://purl.obolibrary.org/obo/HP_0001122">
        <oboInOwl:consider>HP:0000610</oboInOwl:consider>
        <oboInOwl:id>HP:0001122</oboInOwl:id>
        <rdfs:label>obsolete Aplasia/Hypoplasia of the choroid</rdfs:label>
        <owl:deprecated rdf:datatype="http://www.w3.org/2001/XMLSchema#boolean">true</owl:deprecated>
    </owl:Class>

Note: IAO_0000116 (editor note) is used to indicate the 'replaced by' term for some Object Properties (see OBI_0000294 and OBI_0000300 for examples), but there aren't any instances where it was used for classes.