English
If R and S are nonassociative rings, then the product R × S is a nonassociative ring.
Русский
Если R и S — неассоциативные кольца, то их произведение R × S образует неассоциативное кольцо.
LaTeX
$$$[ \\text{NonAssocRing }R] \\; [\\text{NonAssocRing }S] \\; \\Rightarrow\\; \\text{NonAssocRing }(R \\times S). $$$
Lean4
instance instNonAssocRing [NonAssocRing R] [NonAssocRing S] : NonAssocRing (R × S) :=
{ inferInstanceAs (NonUnitalNonAssocRing (R × S)), inferInstanceAs (NonAssocSemiring (R × S)),
inferInstanceAs (AddGroupWithOne (R × S)) with }