ILE Home Intuitionistic Logic Explorer < Previous   Next >
Nearby theorems
Mirrors  >  Home  >  ILE Home  >  Th. List  >  imnan GIF version

Theorem imnan 696
Description: Express implication in terms of conjunction. (Contributed by NM, 9-Apr-1994.) (Revised by Mario Carneiro, 1-Feb-2015.)
Assertion
Ref Expression
imnan ((𝜑 → ¬ 𝜓) ↔ ¬ (𝜑𝜓))

Proof of Theorem imnan
StepHypRef Expression
1 pm3.2im 642 . . . 4 (𝜑 → (𝜓 → ¬ (𝜑 → ¬ 𝜓)))
21imp 124 . . 3 ((𝜑𝜓) → ¬ (𝜑 → ¬ 𝜓))
32con2i 632 . 2 ((𝜑 → ¬ 𝜓) → ¬ (𝜑𝜓))
4 pm3.2 139 . . 3 (𝜑 → (𝜓 → (𝜑𝜓)))
54con3rr3 638 . 2 (¬ (𝜑𝜓) → (𝜑 → ¬ 𝜓))
63, 5impbii 126 1 ((𝜑 → ¬ 𝜓) ↔ ¬ (𝜑𝜓))
Colors of variables: wff set class
Syntax hints:  ¬ wn 3  wi 4  wa 104  wb 105
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 619  ax-in2 620
This theorem depends on definitions:  df-bi 117
This theorem is referenced by:  imnani  697  nan  698  mpnanrd  699  pm3.24  700  imanst  895  ianordc  906  pm5.17dc  911  dn1dc  968  xorbin  1428  xordc1  1437  alinexa  1651  dfrex2dc  2523  ralinexa  2559  rabeq0  3524  disj  3543  minel  3556  disjsn  3731  sotricim  4420  poirr2  5129  funun  5371  imadiflem  5409  imadif  5410  brprcneu  5632  2omotaplemap  7475  prltlu  7706  caucvgprlemnbj  7886  caucvgprprlemnbj  7912  suplocexprlemmu  7937  xrltnsym2  10028  fzp1nel  10338  fsumsplit  11967  sumsplitdc  11992  phiprmpw  12793  odzdvds  12817  pcdvdsb  12892  lgsne0  15766  lgsquadlem3  15807  bj-nnor  16330
  Copyright terms: Public domain W3C validator