2.2.1 Control

sgopn Opens an  output device
sgfrm Sets a frame
sgcls Closes an output device
ipara = NumRu::DCL.sgpget(cp) Inquires about an internal variable
NumRu::DCL.sgpset(cp,lpara) Changes an internal variable
NumRu::DCL.sgpstx(cp,ipara) Changes an internal variable (Permits changes with a runtime option).