Theorem sbcn1 3033

Description: Move negation in and out of class substitution. One direction of sbcng 3026 that holds for proper classes. (Contributed by NM, 17-Aug-2018.)

Assertion

Ref	Expression
sbcn1	|- ( [. A / x ]. -. ph -> -. [. A / x ]. ph )

Proof of Theorem sbcn1

Step	Hyp	Ref	Expression
1		sbcex 2994	. 2 |- ( [. A / x ]. -. ph -> A e. _V )
2		sbcng 3026	. . 3 |- ( A e. _V -> ( [. A / x ]. -. ph <-> -. [. A / x ]. ph ) )
3	2	biimpd 144	. 2 |- ( A e. _V -> ( [. A / x ]. -. ph -> -. [. A / x ]. ph ) )
4	1, 3	mpcom 36	1 |- ( [. A / x ]. -. ph -> -. [. A / x ]. ph )

Syntax hints:   -. wn 3   -> wi 4   e. wcel 2164   _Vcvv 2760   [.wsbc 2985

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-fal 1370  df-nf 1472  df-sb 1774  df-clab 2180  df-cleq 2186  df-clel 2189  df-nfc 2325  df-v 2762  df-sbc 2986

This theorem is referenced by: (None)