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Theorem neeq1 2193
 Description: Equality theorem for inequality. (Contributed by NM, 19-Nov-1994.)
Assertion
Ref Expression
neeq1 (A = B → (A𝐶B𝐶))

Proof of Theorem neeq1
StepHypRef Expression
1 eqeq1 2024 . . 3 (A = B → (A = 𝐶B = 𝐶))
21notbid 579 . 2 (A = B → (¬ A = 𝐶 ↔ ¬ B = 𝐶))
3 df-ne 2184 . 2 (A𝐶 ↔ ¬ A = 𝐶)
4 df-ne 2184 . 2 (B𝐶 ↔ ¬ B = 𝐶)
52, 3, 43bitr4g 212 1 (A = B → (A𝐶B𝐶))
 Colors of variables: wff set class Syntax hints:  ¬ wn 3   → wi 4   ↔ wb 98   = wceq 1226   ≠ wne 2182 This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 99  ax-ia2 100  ax-ia3 101  ax-in1 532  ax-in2 533  ax-5 1312  ax-gen 1314  ax-4 1377  ax-17 1396  ax-ext 2000 This theorem depends on definitions:  df-bi 110  df-cleq 2011  df-ne 2184 This theorem is referenced by:  neeq1i  2195  neeq1d  2198  nelrdva  2719  psseq1  3004  0inp0  3889
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