Theorem eldifad 3165

Description: If a class is in the difference of two classes, it is also in the minuend. One-way deduction form of eldif 3163. (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 3163	. . 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 2164   \ cdif 3151

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 1458  ax-7 1459  ax-gen 1460  ax-ie1 1504  ax-ie2 1505  ax-8 1515  ax-10 1516  ax-11 1517  ax-i12 1518  ax-bndl 1520  ax-4 1521  ax-17 1537  ax-i9 1541  ax-ial 1545  ax-i5r 1546  ax-ext 2175

This theorem depends on definitions:  df-bi 117  df-tru 1367  df-nf 1472  df-sb 1774  df-clab 2180  df-cleq 2186  df-clel 2189  df-nfc 2325  df-v 2762  df-dif 3156

This theorem is referenced by:  fimax2gtri  6959  finexdc  6960  unfidisj  6980  undifdc  6982  ssfirab  6992  fnfi  6997  iunfidisj  7007  dcfi  7042  hashunlem  10878  zfz1isolemiso  10913  fsumrelem  11617  fprodcl2lem  11751  fprodap0  11767  fprodrec  11775  fprodap0f  11782  fprodle  11786  iuncld  14294  fsumcncntop  14746  gausslemma2dlem0i  15214  gausslemma2dlem4  15221  gausslemma2dlem5a  15222  gausslemma2dlem7  15225  lgseisenlem1  15227  lgseisenlem2  15228  lgseisenlem3  15229  lgseisenlem4  15230  lgseisen  15231  lgsquadlem1  15234  lgsquadlem2  15235  lgsquadlem3  15236  bj-charfun  15369