Theorem eldifd 3221

Description: If a class is in one class and not another, it is also in their difference. One-way deduction form of eldif 3220. (Contributed by David Moews, 1-May-2017.)

Hypotheses

Ref	Expression
eldifd.1	⊢ (𝜑 → 𝐴 ∈ 𝐵)
eldifd.2	⊢ (𝜑 → ¬ 𝐴 ∈ 𝐶)

Assertion

Ref	Expression
eldifd	⊢ (𝜑 → 𝐴 ∈ (𝐵 ∖ 𝐶))

Proof of Theorem eldifd

Step	Hyp	Ref	Expression
1		eldifd.1	. 2 ⊢ (𝜑 → 𝐴 ∈ 𝐵)
2		eldifd.2	. 2 ⊢ (𝜑 → ¬ 𝐴 ∈ 𝐶)
3		eldif 3220	. 2 ⊢ (𝐴 ∈ (𝐵 ∖ 𝐶) ↔ (𝐴 ∈ 𝐵 ∧ ¬ 𝐴 ∈ 𝐶))
4	1, 2, 3	sylanbrc 417	1 ⊢ (𝜑 → 𝐴 ∈ (𝐵 ∖ 𝐶))

Syntax hints:  ¬ wn 3   → wi 4   ∈ wcel 2203   ∖ cdif 3208

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-in1 619  ax-in2 620  ax-io 717  ax-5 1496  ax-7 1497  ax-gen 1498  ax-ie1 1542  ax-ie2 1543  ax-8 1553  ax-10 1554  ax-11 1555  ax-i12 1556  ax-bndl 1558  ax-4 1559  ax-17 1575  ax-i9 1579  ax-ial 1583  ax-i5r 1584  ax-ext 2214

This theorem depends on definitions:  df-bi 117  df-tru 1401  df-nf 1510  df-sb 1812  df-clab 2219  df-cleq 2225  df-clel 2228  df-nfc 2373  df-v 2815  df-dif 3213

This theorem is referenced by:  exmidundif  4319  exmidundifim  4320  frirrg  4471  dcdifsnid  6737  phpelm  7121  findcard2d  7148  findcard2sd  7149  diffifi  7151  unsnfidcex  7180  unsnfidcel  7181  undifdcss  7183  difinfsnlem  7390  difinfsn  7391  hashunlem  11168  seq3coll  11214  fsum3cvg  12064  isumss  12077  fisumss  12078  fproddccvg  12258  fprodssdc  12276  sqrt2irr0  12861  nnoddn2prmb  12960  bassetsnn  13269  logbgcd1irr  15832  2lgslem2  15965