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  7583  cauappcvgprlemdisj  7711  caucvgprlemdisj  7734  caucvgprprlemdisj  7762  suplocexprlemdisj  7780  suplocexprlemub  7783  suplocsrlem  7868  resqrexlemgt0  11164  resqrexlemoverl  11165  leabs  11218  climge0  11468  isprm5lem  12279  ennnfonelemex  12571  dedekindeu  14777  dedekindicclemicc  14786  pw1nct  15493