

border {
  center:  hbox {
    grid 4 3 {
      button "7"  button "8"  button "9"
      button "4"  button "5"  button "6"
      button "1"  button "2"  button "3"
      button "0"  space       space
    }

    vbox edged "ops" {
      button "+"  
      button "-"  
      button "*"
      button "/"
    }
  }

  south: textfield 20 ""
}