Theorem eldifsni 3841

Description: Membership in a set with an element removed. (Contributed by NM, 10-Mar-2015.)

Assertion

Ref	Expression
eldifsni	⊢ (A ∈ (B ∖ {C}) → A ≠ C)

Proof of Theorem eldifsni

Step	Hyp	Ref	Expression
1		eldifsn 3840	. 2 ⊢ (A ∈ (B ∖ {C}) ↔ (A ∈ B ∧ A ≠ C))
2	1	simprbi 450	1 ⊢ (A ∈ (B ∖ {C}) → A ≠ C)

Syntax hints:   → wi 4   ∈ wcel 1710   ≠ wne 2517   ∖ cdif 3207  {csn 3738

This theorem was proved from 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-6 1729  ax-7 1734  ax-11 1746  ax-12 1925  ax-ext 2334

This theorem depends on definitions:  df-bi 177  df-or 359  df-an 360  df-nan 1288  df-tru 1319  df-ex 1542  df-nf 1545  df-sb 1649  df-clab 2340  df-cleq 2346  df-clel 2349  df-nfc 2479  df-ne 2519  df-v 2862  df-nin 3212  df-compl 3213  df-in 3214  df-dif 3216  df-sn 3742

This theorem is referenced by:  neldifsn  3842