comprehensionTheorem = [st|
Show EXAx(F(x)/\G(x)<->X(x))
   Show Ax(F(x)/\G(x)<->\y[F(y)/\G(y)](x))
       Show F(c)/\G(c)->\y[F(y)/\G(y)](c)
            F(c)/\G(c):AS
            \y[F(y)/\G(y)](c):ABS 4
       :CD 5
       Show \y[F(y)/\G(y)](c)->F(c)/\G(c)
            \y[F(y)/\G(y)](c):AS
            F(c)/\G(c):APP 8
       :CD 9
       F(c)/\G(c)<->\y[F(y)/\G(y)](c):CB 3 7
   :UD 11
   EXAx(F(x)/\G(x)<->X(x)):EG 2
:DD 13|]
comprehensionTheorem = [st|
Show EXAx(F(x)/\G(x)<->X(x))
   Show Ax(F(x)/\G(x)<->\y[F(y)/\G(y)](x))
       Show F(c)/\G(c)->\y[F(y)/\G(y)](c)
            F(c)/\G(c):AS
            \y[F(y)/\G(y)](c):ABS 4
       :CD 5
       Show \y[F(y)/\G(y)](c)->F(c)/\G(c)
            \y[F(y)/\G(y)](c):AS
            F(c)/\G(c):APP 8
       :CD 9
       F(c)/\G(c)<->\y[F(y)/\G(y)](c):CB 3 7
   :UD 11
   EXAx(F(x)/\G(x)<->X(x)):EG 2
:DD 13|]
comprehensionTheorem = [st|
Show EXAx(F(x)/\G(x)<->X(x))
   Show Ax(F(x)/\G(x)<->\y[F(y)/\G(y)](x))
       Show F(c)/\G(c)->\y[F(y)/\G(y)](c)
            F(c)/\G(c):AS
            \y[F(y)/\G(y)](c):ABS 4
       :CD 5
       Show \y[F(y)/\G(y)](c)->F(c)/\G(c)
            \y[F(y)/\G(y)](c):AS
            F(c)/\G(c):APP 8
       :CD 9
       F(c)/\G(c)<->\y[F(y)/\G(y)](c):CB 3 7
   :UD 11
   EXAx(F(x)/\G(x)<->X(x)):EG 2
:DD 13|]