Theorem eldifd 3164

Description: If a class is in one class and not another, it is also in their difference. One-way deduction form of eldif 3163. (Contributed by David Moews, 1-May-2017.)

Hypotheses

Ref	Expression
eldifd.1	|- ( ph -> A e. B )
eldifd.2	|- ( ph -> -. A e. C )

Assertion

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

Proof of Theorem eldifd

Step	Hyp	Ref	Expression
1		eldifd.1	. 2 |- ( ph -> A e. B )
2		eldifd.2	. 2 |- ( ph -> -. A e. C )
3		eldif 3163	. 2 |- ( A e. ( B \ C ) <-> ( A e. B /\ -. A e. C ) )
4	1, 2, 3	sylanbrc 417	1 |- ( ph -> A e. ( B \ C ) )

Syntax hints:   -. wn 3   -> wi 4   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:  exmidundif  4236  exmidundifim  4237  frirrg  4382  dcdifsnid  6559  phpelm  6924  findcard2d  6949  findcard2sd  6950  diffifi  6952  unsnfidcex  6978  unsnfidcel  6979  undifdcss  6981  difinfsnlem  7160  difinfsn  7161  hashunlem  10878  seq3coll  10916  fsum3cvg  11524  isumss  11537  fisumss  11538  fproddccvg  11718  fprodssdc  11736  sqrt2irr0  12305  nnoddn2prmb  12403  logbgcd1irr  15140  2lgslem2  15249