Modelling tool allows you to use an external Evaluator to evaluate an opaque expression in your model. Therefore, you can use any language supported by the external Evaluator in the body of the opaque expression.
You must specify the name of the language in the opaque expression. If you do not specify the language of the opaque expression, will use the Default Language specified in Simulation Framework in the Environment Options dialog as follows.
The Default Language property in the Environment Options dialog.
If the language of expressions of constraints of a SysML Constraint Block is not specified, modeling tool will use the Evaluator, specified in Default Parametric Evaluator in the Environment Options dialog, to solve the expressions as follows.
The Default Parametric Evaluator property in the Environment Options dialog.