`UNION``f``g`procedureConstructs a signal function whose input is the union of the inputs of signal functions

`f`and`g`, and whose output is the union of the outputs of`f`and`g`.

`UNION``f``g`procedureConstructs a signal function whose input is the union of the inputs of signal functions

`f`and`g`, and whose output is the union of the outputs of`f`and`g`.