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Theorem eqnetrd 2535
Description: Substitution of equal classes into an inequality. (Contributed by NM, 4-Jul-2012.)
Hypotheses
Ref Expression
eqnetrd.1 ⊢ (φ → A = B)
eqnetrd.2 ⊢ (φ → B ≠ C)
Assertion
Ref Expression
eqnetrd ⊢ (φ → A ≠ C)

Proof of Theorem eqnetrd
StepHypRef Expression
1 eqnetrd.2 . 2 ⊢ (φ → B ≠ C)
2 eqnetrd.1 . . 3 ⊢ (φ → A = B)
32neeq1d 2530 . 2 ⊢ (φ → (A ≠ C ↔ B ≠ C))
41, 3mpbird 223 1 ⊢ (φ → A ≠ C)
Colors of variables:    wff setvar class
This proof depends on syntax axioms:   → wi 4   = wceq 1642   ≠ wne 2517
This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1546  ax-5 1557  ax-17 1616  ax-9 1654  ax-8 1675  ax-11 1746  ax-ext 2334
This proof depends on definitions:  df-bi 177  df-ex 1542  df-cleq 2346  df-ne 2519
This theorem is used by:  eqnetrrd  2537  vfin1cltv  4548  nchoicelem12  6301  nchoicelem14  6303  nchoicelem17  6306
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