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Theorem df3nandALT1 14146
Description: The double nand expressed in terms of pure nand.
Assertion
Ref Expression
df3nandALT1 |- ((ph -/\ ps -/\ ch) <-> (ph -/\ ((ps -/\ ch) -/\ (ps -/\ ch))))

Proof of Theorem df3nandALT1
StepHypRef Expression
1 iman 256 . . 3 |- ((ph -> ((ps -/\ ch) /\ (ps -/\ ch))) <-> -. (ph /\ -. ((ps -/\ ch) /\ (ps -/\ ch))))
2 imnan 261 . . . . . . . 8 |- ((ps -> -. ch) <-> -. (ps /\ ch))
32biimpi 168 . . . . . . 7 |- ((ps -> -. ch) -> -. (ps /\ ch))
43, 3jca 310 . . . . . 6 |- ((ps -> -. ch) -> (-. (ps /\ ch) /\ -. (ps /\ ch)))
52biimpri 169 . . . . . . 7 |- (-. (ps /\ ch) -> (ps -> -. ch))
65adantl 424 . . . . . 6 |- ((-. (ps /\ ch) /\ -. (ps /\ ch)) -> (ps -> -. ch))
74, 6impbii 174 . . . . 5 |- ((ps -> -. ch) <-> (-. (ps /\ ch) /\ -. (ps /\ ch)))
8 df-nand 1230 . . . . . 6 |- ((ps -/\ ch) <-> -. (ps /\ ch))
98, 8anbi12i 540 . . . . 5 |- (((ps -/\ ch) /\ (ps -/\ ch)) <-> (-. (ps /\ ch) /\ -. (ps /\ ch)))
107, 9bitr4i 193 . . . 4 |- ((ps -> -. ch) <-> ((ps -/\ ch) /\ (ps -/\ ch)))
1110imbi2i 202 . . 3 |- ((ph -> (ps -> -. ch)) <-> (ph -> ((ps -/\ ch) /\ (ps -/\ ch))))
12 df-nand 1230 . . . . 5 |- (((ps -/\ ch) -/\ (ps -/\ ch)) <-> -. ((ps -/\ ch) /\ (ps -/\ ch)))
1312anbi2i 538 . . . 4 |- ((ph /\ ((ps -/\ ch) -/\ (ps -/\ ch))) <-> (ph /\ -. ((ps -/\ ch) /\ (ps -/\ ch))))
1413notbii 204 . . 3 |- (-. (ph /\ ((ps -/\ ch) -/\ (ps -/\ ch))) <-> -. (ph /\ -. ((ps -/\ ch) /\ (ps -/\ ch))))
151, 11, 143bitr4i 200 . 2 |- ((ph -> (ps -> -. ch)) <-> -. (ph /\ ((ps -/\ ch) -/\ (ps -/\ ch))))
16 df-3nand 14145 . 2 |- ((ph -/\ ps -/\ ch) <-> (ph -> (ps -> -. ch)))
17 df-nand 1230 . 2 |- ((ph -/\ ((ps -/\ ch) -/\ (ps -/\ ch))) <-> -. (ph /\ ((ps -/\ ch) -/\ (ps -/\ ch))))
1815, 16, 173bitr4i 200 1 |- ((ph -/\ ps -/\ ch) <-> (ph -/\ ((ps -/\ ch) -/\ (ps -/\ ch))))
Colors of variables: wff set class
Syntax hints:  -. wn 2   -> wi 3   <-> wb 163   /\ wa 240   -/\ wnand 1229   -/\ w3nand 14144
This theorem was proved from axioms:  ax-1 4  ax-2 5  ax-3 6  ax-mp 7
This theorem depends on definitions:  df-bi 164  df-an 242  df-nand 1230  df-3nand 14145
Copyright terms: Public domain