Theorem inegd 1383

Description: Negation introduction rule from natural deduction. (Contributed by Mario Carneiro, 9-Feb-2017.)

Hypothesis

Ref	Expression
inegd.1	|- ( ( ph /\ ps ) -> F. )

Assertion

Ref	Expression
inegd	|- ( ph -> -. ps )

Proof of Theorem inegd

Step	Hyp	Ref	Expression
1		inegd.1	. . 3 |- ( ( ph /\ ps ) -> F. )
2	1	ex 115	. 2 |- ( ph -> ( ps -> F. ) )
3		dfnot 1382	. 2 |- ( -. ps <-> ( ps -> F. ) )
4	2, 3	sylibr 134	1 |- ( ph -> -. ps )

Syntax hints:   -. wn 3   -> wi 4   /\ wa 104   F. wfal 1369

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

This theorem depends on definitions:  df-bi 117  df-tru 1367  df-fal 1370

This theorem is referenced by:  genpdisj  7607  cauappcvgprlemdisj  7735  caucvgprlemdisj  7758  caucvgprprlemdisj  7786  suplocexprlemdisj  7804  suplocexprlemub  7807  suplocsrlem  7892  resqrexlemgt0  11202  resqrexlemoverl  11203  leabs  11256  climge0  11507  isprm5lem  12334  ennnfonelemex  12656  dedekindeu  14943  dedekindicclemicc  14952  pw1nct  15734