PMC:1315279 / 434-437 JSONTXT

{"project":"craft-sa-dev","denotations":[{"id":"T314","span":{"begin":2,"end":3},"obj":"SYM"}],"text":"68−"}

{"project":"craft-ca-core-ex-dev","denotations":[{"id":"T145","span":{"begin":2,"end":3},"obj":"SO_EXT:sequence_nullness_or_absence"}],"text":"68−"}