Theorem eldifad 3177

Description: If a class is in the difference of two classes, it is also in the minuend. One-way deduction form of eldif 3175. (Contributed by David Moews, 1-May-2017.)

Hypothesis

Ref	Expression
eldifad.1	⊢ (𝜑 → 𝐴 ∈ (𝐵 ∖ 𝐶))

Assertion

Ref	Expression
eldifad	⊢ (𝜑 → 𝐴 ∈ 𝐵)

Proof of Theorem eldifad

Step	Hyp	Ref	Expression
1		eldifad.1	. . 3 ⊢ (𝜑 → 𝐴 ∈ (𝐵 ∖ 𝐶))
2		eldif 3175	. . 3 ⊢ (𝐴 ∈ (𝐵 ∖ 𝐶) ↔ (𝐴 ∈ 𝐵 ∧ ¬ 𝐴 ∈ 𝐶))
3	1, 2	sylib 122	. 2 ⊢ (𝜑 → (𝐴 ∈ 𝐵 ∧ ¬ 𝐴 ∈ 𝐶))
4	3	simpld 112	1 ⊢ (𝜑 → 𝐴 ∈ 𝐵)

Syntax hints:  ¬ wn 3   → wi 4   ∧ wa 104   ∈ wcel 2176   ∖ cdif 3163

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 711  ax-5 1470  ax-7 1471  ax-gen 1472  ax-ie1 1516  ax-ie2 1517  ax-8 1527  ax-10 1528  ax-11 1529  ax-i12 1530  ax-bndl 1532  ax-4 1533  ax-17 1549  ax-i9 1553  ax-ial 1557  ax-i5r 1558  ax-ext 2187

This theorem depends on definitions:  df-bi 117  df-tru 1376  df-nf 1484  df-sb 1786  df-clab 2192  df-cleq 2198  df-clel 2201  df-nfc 2337  df-v 2774  df-dif 3168

This theorem is referenced by:  fimax2gtri  6998  finexdc  6999  unfidisj  7019  undifdc  7021  ssfirab  7033  fnfi  7038  iunfidisj  7048  dcfi  7083  hashunlem  10949  zfz1isolemiso  10984  fsumrelem  11782  fprodcl2lem  11916  fprodap0  11932  fprodrec  11940  fprodap0f  11947  fprodle  11951  iuncld  14587  fsumcncntop  15039  gausslemma2dlem0i  15534  gausslemma2dlem4  15541  gausslemma2dlem5a  15542  gausslemma2dlem7  15545  lgseisenlem1  15547  lgseisenlem2  15548  lgseisenlem3  15549  lgseisenlem4  15550  lgseisen  15551  lgsquadlem1  15554  lgsquadlem2  15555  lgsquadlem3  15556  bj-charfun  15743