Theorem eldifd 3163

Description: If a class is in one class and not another, it is also in their difference. One-way deduction form of eldif 3162. (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 3162	. 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 3150

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 3155

This theorem is referenced by:  exmidundif  4235  exmidundifim  4236  frirrg  4381  dcdifsnid  6557  phpelm  6922  findcard2d  6947  findcard2sd  6948  diffifi  6950  unsnfidcex  6976  unsnfidcel  6977  undifdcss  6979  difinfsnlem  7158  difinfsn  7159  hashunlem  10875  seq3coll  10913  fsum3cvg  11521  isumss  11534  fisumss  11535  fproddccvg  11715  fprodssdc  11733  sqrt2irr0  12302  nnoddn2prmb  12400  logbgcd1irr  15099