;;; -*- logo -*-

to setpen :pen_data
ifelse equalp first bf :pen_data "reverse ~
       [penreverse] ~
       [ifelse equalp first bf :pen_data "erase ~
               [penerase] ~
               [penpaint]]
ifelse equalp first :pen_data "penup [penup] [pendown]
setpensize first bf bf :pen_data
setpencolor first bf bf bf :pen_data
setpenpattern first bf bf bf bf :pen_data
end

bury [setpen]