Theorem sbcn1 3002

Description: Move negation in and out of class substitution. One direction of sbcng 2995 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 2963	. 2 |- ( [. A / x ]. -. ph -> A e. _V )
2		sbcng 2995	. . 3 |- ( A e. _V -> ( [. A / x ]. -. ph <-> -. [. A / x ]. ph ) )
3	2	biimpd 143	. 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 2141   _Vcvv 2730   [.wsbc 2955

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-in1 609  ax-in2 610  ax-io 704  ax-5 1440  ax-7 1441  ax-gen 1442  ax-ie1 1486  ax-ie2 1487  ax-8 1497  ax-10 1498  ax-11 1499  ax-i12 1500  ax-bndl 1502  ax-4 1503  ax-17 1519  ax-i9 1523  ax-ial 1527  ax-i5r 1528  ax-ext 2152

This theorem depends on definitions:  df-bi 116  df-tru 1351  df-fal 1354  df-nf 1454  df-sb 1756  df-clab 2157  df-cleq 2163  df-clel 2166  df-nfc 2301  df-v 2732  df-sbc 2956

This theorem is referenced by: (None)