English
If α is a Semiring with the usual order conditions, then WithTop α is a Semiring.
Русский
Если α является полугруппой полукольцом (Semiring) с обычным порядком, то WithTop α — тоже Semiring.
LaTeX
$$$\\\\mathrm{WithTop} \\alpha \\\\text{ is a Semiring if } \\alpha \\\\text{ is}$$$
Lean4
instance instSemiring [Semiring α] [PartialOrder α] [CanonicallyOrderedAdd α] [NoZeroDivisors α] [Nontrivial α] :
Semiring (WithTop α) where
toNonUnitalSemiring := WithTop.instNonUnitalSemiring
__ := WithTop.instMonoidWithZero
__ := WithTop.addCommMonoidWithOne