Where used: Operation Model

constrainsVariableValue / hasValueConstrainedBy

Object Type constrainsVariableValue Variable

Variable hasValueConstrainedBy Object Type

This specifies that a variable of an operation is constrained to be of
certain type.

The minimum cardinality is zero on the Object Type side to allow for
untyped languages.  Alternatively, we could require a object type to
constrain the value, but allow it to be the meta-type Object from the