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Theorem helloworld 30931
Description: The classic "Hello world" benchmark has been translated into 314 computer programming languages - see http://helloworldcollection.de. However, for many years it eluded a proof that it is more than just a conjecture, even though a wily mathematician once claimed, "I have discovered a truly marvelous proof of this, which this margin is too narrow to contain." Using an IBM 709 mainframe, a team of mathematicians led by Prof. Loof Lirpa, at the New College of Tahiti, were finally able to put it to rest with a remarkably short proof only four lines long. (Contributed by Prof. Loof Lirpa, 1-Apr-2007.) (Proof modification is discouraged.) (New usage is discouraged.)
Assertion
Ref Expression
helloworld ¬ ( ∈ (𝐿𝐿0) ∧ 𝑊∅(R1𝑑))

Proof of Theorem helloworld
StepHypRef Expression
1 noel 4287 . . 3 ¬ ⟨𝑊, (R1𝑑)⟩ ∈ ∅
2 df-br 5108 . . 3 (𝑊∅(R1𝑑) ↔ ⟨𝑊, (R1𝑑)⟩ ∈ ∅)
31, 2mtbir 326 . 2 ¬ 𝑊∅(R1𝑑)
43intnan 492 1 ¬ ( ∈ (𝐿𝐿0) ∧ 𝑊∅(R1𝑑))
Colors of variables:    wff setvar class
This proof depends on syntax axioms:  ¬ wn 3  wa 401  wcel 2145  c0 4282  cop 4593   class class class wbr 5107  (class class class)co 7416  Rcnr 10877  0cc0 11127  1c1 11128
This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1828  ax-4 1842  ax-5 1943  ax-6 2000  ax-7 2041  ax-8 2147  ax-9 2155  ax-ext 2734
This proof depends on definitions:  df-bi 210  df-an 402  df-tru 1573  df-fal 1583  df-ex 1813  df-sb 2100  df-clab 2741  df-cleq 2754  df-clel 2837  df-dif 3905  df-nul 4283  df-br 5108
This theorem is used by: (None)
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