# `NeZero` typeclass #

We give basic facts about the `NeZero n` typeclass.

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theorem not_neZero {R : Type u_1} [Zero R] {n : R} :
¬NeZero n ↔ n = 0
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theorem eq_zero_or_neZero {R : Type u_1} [Zero R] (a : R) :
a = 0 ∨ NeZero a
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@[simp]
theorem zero_ne_one {α : Type u_2} [Zero α] [One α] [NeZero 1] :
0 ≠ 1
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@[simp]
theorem one_ne_zero {α : Type u_2} [Zero α] [One α] [NeZero 1] :
1 ≠ 0
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theorem ne_zero_of_eq_one {α : Type u_2} [Zero α] [One α] [NeZero 1] {a : α} (h : a = 1) :
a ≠ 0
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theorem two_ne_zero {α : Type u_2} [Zero α] [OfNat α 2] [NeZero 2] :
2 ≠ 0
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theorem three_ne_zero {α : Type u_2} [Zero α] [OfNat α 3] [NeZero 3] :
3 ≠ 0
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theorem four_ne_zero {α : Type u_2} [Zero α] [OfNat α 4] [NeZero 4] :
4 ≠ 0
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theorem zero_ne_one' (α : Type u_2) [Zero α] [One α] [NeZero 1] :
0 ≠ 1
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theorem one_ne_zero' (α : Type u_2) [Zero α] [One α] [NeZero 1] :
1 ≠ 0
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theorem two_ne_zero' (α : Type u_2) [Zero α] [OfNat α 2] [NeZero 2] :
2 ≠ 0
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theorem three_ne_zero' (α : Type u_2) [Zero α] [OfNat α 3] [NeZero 3] :
3 ≠ 0
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theorem four_ne_zero' (α : Type u_2) [Zero α] [OfNat α 4] [NeZero 4] :
4 ≠ 0
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theorem NeZero.of_pos {M : Type u_2} {x : M} [Preorder M] [Zero M] (h : 0 < x) :
NeZero x