Typeclass One

Zero has already been defined in Lean.

class One (α : Type u) : Type u

• one : α

@[instance 300]

instance One.toOfNat1 {α : Type u_1} [One α] : OfNat α 1

Equations

• One.toOfNat1 = { ofNat := One.one }

@[instance 200]

instance One.ofOfNat1 {α : Type u_1} [OfNat α 1] : One α

Equations

• One.ofOfNat1 = { one := 1 }

@[instance 20]

instance Zero.instNonempty {α : Type u} [Zero α] : Nonempty α

@[instance 20]

instance One.instNonempty {α : Type u} [One α] : Nonempty α

theorem Subsingleton.eq_one {α : Type u} [One α] [Subsingleton α] (a : α) : a = 1

theorem Subsingleton.eq_zero {α : Type u} [Zero α] [Subsingleton α] (a : α) : a = 0