Theorem nemtbir 3021

Description: An inference from an inequality, related to modus tollens. (Contributed by NM, 13-Apr-2007.)

Hypotheses

Ref	Expression
nemtbir.1	⊢ 𝐴 ≠ 𝐵
nemtbir.2	⊢ (𝜑 ↔ 𝐴 = 𝐵)

Assertion

Ref	Expression
nemtbir	⊢ ¬ 𝜑

Proof of Theorem nemtbir

Step	Hyp	Ref	Expression
1		nemtbir.1	. . 3 ⊢ 𝐴 ≠ 𝐵
2	1	neii 2927	. 2 ⊢ ¬ 𝐴 = 𝐵
3		nemtbir.2	. 2 ⊢ (𝜑 ↔ 𝐴 = 𝐵)
4	2, 3	mtbir 323	1 ⊢ ¬ 𝜑

Syntax hints:  ¬ wn 3   ↔ wb 206   = wceq 1540   ≠ wne 2925

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8

This theorem depends on definitions:  df-bi 207  df-ne 2926

This theorem is referenced by:  opthwiener  5474  opthprc  5702  ord2eln012  8461  0sdom1dom  9185  cfpwsdom  10537  fprodn0f  15957  m1exp1  16346  pmtrsn  19449  gzrngunitlem  21349  logbmpt  26698  sltval2  27568  sltsolem1  27587  nolt02o  27607  ex-id  30363  ex-mod  30378  coss0  38470  ensucne0  43518  clsk1indlem4  44033  clsk1indlem1  44034  etransc  46281