Can't quite run that yet, because

F# error at line 4:
The namespace 'UI' is not defined. (FS39)
F# error at line 5:
The namespace 'UI' is not defined. (FS39)
F# error at line 6:
The namespace 'UI' is not defined. (FS39)
F# error at line 12:
The value, namespace, type or module 'attr' is not defined. (FS39)
F# error at line 13:
The value, namespace, type or module 'Var' is not defined. (FS39)
F# error at line 15:
The value or constructor 'divAttr' is not defined. (FS39)
F# error at line 35:
The value, namespace, type or module 'View' is not defined. (FS39)
F# error at line 38:
The value, namespace, type or module 'View' is not defined. (FS39)
F# error at line 40:
The value, namespace, type or module 'View' is not defined. (FS39)
F# error at line 42:
The value, namespace, type or module 'View' is not defined. (FS39)
F# error at line 44:
The value, namespace, type or module 'View' is not defined. (FS39)
F# error at line 46:
The value, namespace, type or module 'View' is not defined. (FS39)
F# error at line 58:
The value or constructor 'tr' is not defined. (FS39)
F# error at line 63:
The type 'Doc' is not defined. (FS39)
F# error at line 66:
The value or constructor 'divAttr' is not defined. (FS39)
F# error at line 82:
The value or constructor 'div' is not defined. (FS39)
F# error at line 87:
The value, namespace, type or module 'Doc' is not defined. (FS39)