mathlib

762fc150 - feat(set_theory/ordinal/arithmetic): Add missing instances for `ordinal` (#14128)

feat(set_theory/ordinal/arithmetic): Add missing instances for `ordinal` (#14128) We add the following instances: - `monoid_with_zero ordinal` - `no_zero_divisors ordinal` - `is_left_distrib_class ordinal` - `contravariant_class ordinal ordinal (swap (+)) (<)` - `is_antisymm ordinal (∣)`