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Theorem zeneo 12638
Description: No even integer equals an odd integer (i.e. no integer can be both even and odd). Exercise 10(a) of [Apostol] p. 28. This variant of zneo 9747 follows immediately from the fact that a contradiction implies anything, see pm2.21i 655. (Contributed by AV, 22-Jun-2021.)
Assertion
Ref Expression
zeneo  |-  ( ( A  e.  ZZ  /\  B  e.  ZZ )  ->  ( ( 2  ||  A  /\  -.  2  ||  B )  ->  A  =/=  B ) )

Proof of Theorem zeneo
StepHypRef Expression
1 nbrne1 4149 . 2  |-  ( ( 2  ||  A  /\  -.  2  ||  B )  ->  A  =/=  B
)
21a1i 9 1  |-  ( ( A  e.  ZZ  /\  B  e.  ZZ )  ->  ( ( 2  ||  A  /\  -.  2  ||  B )  ->  A  =/=  B ) )
Colors of variables:    wff set class
This proof depends on syntax axioms:   -. wn 3    -> wi 4    /\ wa 104    e. wcel 2209    =/= wne 2420   class class class wbr 4130   2c2 9355   ZZcz 9644    || cdvds 12554
This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-in1 623  ax-in2 624  ax-io 721  ax-5 1500  ax-7 1501  ax-gen 1502  ax-ie1 1546  ax-ie2 1547  ax-8 1557  ax-10 1558  ax-11 1559  ax-i12 1560  ax-bndl 1562  ax-4 1563  ax-17 1579  ax-i9 1583  ax-ial 1587  ax-i5r 1588  ax-ext 2220
This proof depends on definitions:  df-bi 117  df-3an 1011  df-tru 1405  df-nf 1514  df-sb 1816  df-clab 2225  df-cleq 2231  df-clel 2234  df-nfc 2381  df-ne 2421  df-v 2823  df-un 3224  df-sn 3715  df-pr 3716  df-op 3718  df-br 4131
This theorem is used by: (None)
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