Theorem eldifad 3208

Description: If a class is in the difference of two classes, it is also in the minuend. One-way deduction form of eldif 3206. (Contributed by David Moews, 1-May-2017.)

Hypothesis

Ref	Expression
eldifad.1	|- ( ph -> A e. ( B \ C ) )

Assertion

Ref	Expression
eldifad	|- ( ph -> A e. B )

Proof of Theorem eldifad

Step	Hyp	Ref	Expression
1		eldifad.1	. . 3 |- ( ph -> A e. ( B \ C ) )
2		eldif 3206	. . 3 |- ( A e. ( B \ C ) <-> ( A e. B /\ -. A e. C ) )
3	1, 2	sylib 122	. 2 |- ( ph -> ( A e. B /\ -. A e. C ) )
4	3	simpld 112	1 |- ( ph -> A e. B )

Syntax hints:   -. wn 3   -> wi 4   /\ wa 104   e. wcel 2200   \ cdif 3194

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 617  ax-in2 618  ax-io 714  ax-5 1493  ax-7 1494  ax-gen 1495  ax-ie1 1539  ax-ie2 1540  ax-8 1550  ax-10 1551  ax-11 1552  ax-i12 1553  ax-bndl 1555  ax-4 1556  ax-17 1572  ax-i9 1576  ax-ial 1580  ax-i5r 1581  ax-ext 2211

This theorem depends on definitions:  df-bi 117  df-tru 1398  df-nf 1507  df-sb 1809  df-clab 2216  df-cleq 2222  df-clel 2225  df-nfc 2361  df-v 2801  df-dif 3199

This theorem is referenced by:  fimax2gtri  7063  finexdc  7064  unfidisj  7084  undifdc  7086  ssfirab  7098  fnfi  7103  iunfidisj  7113  dcfi  7148  hashunlem  11026  zfz1isolemiso  11061  fsumrelem  11982  fprodcl2lem  12116  fprodap0  12132  fprodrec  12140  fprodap0f  12147  fprodle  12151  iuncld  14789  fsumcncntop  15241  gausslemma2dlem0i  15736  gausslemma2dlem4  15743  gausslemma2dlem5a  15744  gausslemma2dlem7  15747  lgseisenlem1  15749  lgseisenlem2  15750  lgseisenlem3  15751  lgseisenlem4  15752  lgseisen  15753  lgsquadlem1  15756  lgsquadlem2  15757  lgsquadlem3  15758  bj-charfun  16170