Theorem eldifd 3184

Description: If a class is in one class and not another, it is also in their difference. One-way deduction form of eldif 3183. (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 3183	. 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 2178   \ cdif 3171

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 1471  ax-7 1472  ax-gen 1473  ax-ie1 1517  ax-ie2 1518  ax-8 1528  ax-10 1529  ax-11 1530  ax-i12 1531  ax-bndl 1533  ax-4 1534  ax-17 1550  ax-i9 1554  ax-ial 1558  ax-i5r 1559  ax-ext 2189

This theorem depends on definitions:  df-bi 117  df-tru 1376  df-nf 1485  df-sb 1787  df-clab 2194  df-cleq 2200  df-clel 2203  df-nfc 2339  df-v 2778  df-dif 3176

This theorem is referenced by:  exmidundif  4266  exmidundifim  4267  frirrg  4415  dcdifsnid  6613  phpelm  6989  findcard2d  7014  findcard2sd  7015  diffifi  7017  unsnfidcex  7043  unsnfidcel  7044  undifdcss  7046  difinfsnlem  7227  difinfsn  7228  hashunlem  10986  seq3coll  11024  fsum3cvg  11804  isumss  11817  fisumss  11818  fproddccvg  11998  fprodssdc  12016  sqrt2irr0  12601  nnoddn2prmb  12700  logbgcd1irr  15554  2lgslem2  15684