Metamath Proof Explorer


Theorem 1ne0sr

Description: 1 and 0 are distinct for signed reals. (Contributed by NM, 26-Mar-1996) (New usage is discouraged.)

Ref Expression
Assertion 1ne0sr ⊢ ¬ 1 𝑹 = 0 𝑹

Proof

Step Hyp Ref Expression
1 ltsosr ⊢ < 𝑹 Or 𝑹
2 1sr ⊢ 1 𝑹 ∈ 𝑹
3 sonr ⊢ < 𝑹 Or 𝑹 ∧ 1 𝑹 ∈ 𝑹 → ¬ 1 𝑹 < 𝑹 1 𝑹
4 1 2 3 mp2an ⊢ ¬ 1 𝑹 < 𝑹 1 𝑹
5 0lt1sr ⊢ 0 𝑹 < 𝑹 1 𝑹
6 breq1 ⊢ 1 𝑹 = 0 𝑹 → 1 𝑹 < 𝑹 1 𝑹 ↔ 0 𝑹 < 𝑹 1 𝑹
7 5 6 mpbiri ⊢ 1 𝑹 = 0 𝑹 → 1 𝑹 < 𝑹 1 𝑹
8 4 7 mto ⊢ ¬ 1 𝑹 = 0 𝑹