how Ax[]Fx->[]AxFx  /0   :CD
  Ax[]Fx             /0   :AS
  Show []AxFx        /0   :ND
    Show AxFx        /0-1 :UD
      Show Fa        /0-1 :DD
        []Fa         /0   :AO 2
        Fa           /0-1 :[]O 6|]

bisectorTheorem = [s
barcanTheorem = [st|
Show Ax[]Fx->[]AxFx  /0   :CD
  Ax[]Fx             /0   :AS
  Show []AxFx        /0   :ND
    Show AxFx        /0-1 :UD
      Show Fa        /0-1 :DD
        []Fa         /0   :AO 2
        Fa           /0-1 :[]O 6|]
barcanTheorem = [st|
Show Ax[]Fx->[]AxFx  /0   :CD
  Ax[]Fx             /0   :AS
  Show []AxFx        /0   :ND
    Show AxFx        /0-1 :UD
      Show Fa        /0-1 :DD
        []Fa         /0   :AO 2
        Fa           /0-1 :[]O 6|]