Theorem eldifd 3167

Description: If a class is in one class and not another, it is also in their difference. One-way deduction form of eldif 3166. (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 3166	. 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 2167   ∖ cdif 3154

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 615  ax-in2 616  ax-io 710  ax-5 1461  ax-7 1462  ax-gen 1463  ax-ie1 1507  ax-ie2 1508  ax-8 1518  ax-10 1519  ax-11 1520  ax-i12 1521  ax-bndl 1523  ax-4 1524  ax-17 1540  ax-i9 1544  ax-ial 1548  ax-i5r 1549  ax-ext 2178

This theorem depends on definitions:  df-bi 117  df-tru 1367  df-nf 1475  df-sb 1777  df-clab 2183  df-cleq 2189  df-clel 2192  df-nfc 2328  df-v 2765  df-dif 3159

This theorem is referenced by:  exmidundif  4240  exmidundifim  4241  frirrg  4386  dcdifsnid  6571  phpelm  6936  findcard2d  6961  findcard2sd  6962  diffifi  6964  unsnfidcex  6990  unsnfidcel  6991  undifdcss  6993  difinfsnlem  7174  difinfsn  7175  hashunlem  10913  seq3coll  10951  fsum3cvg  11560  isumss  11573  fisumss  11574  fproddccvg  11754  fprodssdc  11772  sqrt2irr0  12357  nnoddn2prmb  12456  logbgcd1irr  15287  2lgslem2  15417