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