Theorem eldifd 3121

Description: If a class is in one class and not another, it is also in their difference. One-way deduction form of eldif 3120. (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 3120	. 2 ⊢ (𝐴 ∈ (𝐵 ∖ 𝐶) ↔ (𝐴 ∈ 𝐵 ∧ ¬ 𝐴 ∈ 𝐶))
4	1, 2, 3	sylanbrc 414	1 ⊢ (𝜑 → 𝐴 ∈ (𝐵 ∖ 𝐶))

Syntax hints:  ¬ wn 3   → wi 4   ∈ wcel 2135   ∖ cdif 3108

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-in1 604  ax-in2 605  ax-io 699  ax-5 1434  ax-7 1435  ax-gen 1436  ax-ie1 1480  ax-ie2 1481  ax-8 1491  ax-10 1492  ax-11 1493  ax-i12 1494  ax-bndl 1496  ax-4 1497  ax-17 1513  ax-i9 1517  ax-ial 1521  ax-i5r 1522  ax-ext 2146

This theorem depends on definitions:  df-bi 116  df-tru 1345  df-nf 1448  df-sb 1750  df-clab 2151  df-cleq 2157  df-clel 2160  df-nfc 2295  df-v 2723  df-dif 3113

This theorem is referenced by:  exmidundif  4179  exmidundifim  4180  frirrg  4322  dcdifsnid  6463  phpelm  6823  findcard2d  6848  findcard2sd  6849  diffifi  6851  unsnfidcex  6876  unsnfidcel  6877  undifdcss  6879  difinfsnlem  7055  difinfsn  7056  hashunlem  10706  seq3coll  10741  fsum3cvg  11305  isumss  11318  fisumss  11319  fproddccvg  11499  fprodssdc  11517  sqrt2irr0  12073  nnoddn2prmb  12171  logbgcd1irr  13426