Summary
- tuned proof
- euclidean rings need no normalization
- prefer official global interface to remove code equations, leaving problematic situation due to bypassing of native code declarations as it is
- elementary definition of division on natural numbers
- removed unused lemmas
- tuned proofs
- avoid name clashes on interpretation of abstract locales
- abolished (semi)ring_div in favour of euclidean_(semi)ring_cancel
- Polynomial_Factorial does not depend on Field_as_Ring as such
- avoid unnecessary qualification