instance
Fintype.IsSquare.decidablePred
{α : Type u_1}
[Mul α]
[Fintype α]
[DecidableEq α]
:
DecidablePred IsSquare
Equations
- Fintype.IsSquare.decidablePred x = Fintype.decidableExistsFintype
The cardinality of Fin 2 is even, Fact version.
This Fact is needed as an instance by Matrix.SpecialLinearGroup.instNeg.
Equations
- Fintype.card_fin_two = (_ : Fact (Even (Fintype.card (Fin 2))))