The diagramming notation described in this document can also be used to describe the relationship between two different SNOMED CT expressions.
This is represented by two expression diagrams, one above the other, separated by a relational operator between. The diagram is read top to bottom.
Figure 3.3-1: Expression relation diagram
As an example below is a diagram showing two expressions that are equivalent:
Figure 3.3-2: Diagram showing equivalence of two expressions
Note that in this example the equivalence relation connects the two expressions with lines – indicating that the relationship is bidirectional and can be read either way.
Figure 3.3-3: _Ref347417159Figure 11 Diagram showing an expression subsumed by and other expression
Figure 3.3-5: _Ref347417377Figure 12 Diagram showing an expression that subsumes another expression