Theorem eldifbd 3210

Description: If a class is in the difference of two classes, it is not in the subtrahend. One-way deduction form of eldif 3207. (Contributed by David Moews, 1-May-2017.)

Hypothesis

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

Assertion

Ref	Expression
eldifbd	|- ( ph -> -. A e. C )

Proof of Theorem eldifbd

Step	Hyp	Ref	Expression
1		eldifbd.1	. . 3 |- ( ph -> A e. ( B \ C ) )
2		eldif 3207	. . 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	simprd 114	1 |- ( ph -> -. A e. C )

Syntax hints:   -. wn 3   -> wi 4   /\ wa 104   e. wcel 2200   \ cdif 3195

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 2802  df-dif 3200

This theorem is referenced by:  fidifsnen  7052  fiunsnnn  7063  fimax2gtri  7084  unfidisj  7107  ssfirab  7121  fnfi  7126  iunfidisj  7136  hashunlem  11057  hashxp  11080  zfz1isolemiso  11093  fsumconst  12005  fsumrelem  12022  fprodcl2lem  12156  fprodconst  12171  fprodap0  12172  fprodrec  12180  fprodap0f  12187  fprodle  12191  fprodmodd  12192  fsumcncntop  15281  1loopgrvd0fi  16112  bj-charfun  16338  bj-charfundc  16339