Description: Lemma 4 for wrd2f1tovbij . (Contributed by Alexander van der Vekens, 28-Jul-2018)
Ref | Expression | ||
---|---|---|---|
Hypotheses | wwlktovf1o.d | |- D = { w e. Word V | ( ( # ` w ) = 2 /\ ( w ` 0 ) = P /\ { ( w ` 0 ) , ( w ` 1 ) } e. X ) } |
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wwlktovf1o.r | |- R = { n e. V | { P , n } e. X } |
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wwlktovf1o.f | |- F = ( t e. D |-> ( t ` 1 ) ) |
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Assertion | wwlktovf1o | |- ( P e. V -> F : D -1-1-onto-> R ) |
Step | Hyp | Ref | Expression |
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1 | wwlktovf1o.d | |- D = { w e. Word V | ( ( # ` w ) = 2 /\ ( w ` 0 ) = P /\ { ( w ` 0 ) , ( w ` 1 ) } e. X ) } |
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2 | wwlktovf1o.r | |- R = { n e. V | { P , n } e. X } |
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3 | wwlktovf1o.f | |- F = ( t e. D |-> ( t ` 1 ) ) |
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4 | 1 2 3 | wwlktovf1 | |- F : D -1-1-> R |
5 | 4 | a1i | |- ( P e. V -> F : D -1-1-> R ) |
6 | 1 2 3 | wwlktovfo | |- ( P e. V -> F : D -onto-> R ) |
7 | df-f1o | |- ( F : D -1-1-onto-> R <-> ( F : D -1-1-> R /\ F : D -onto-> R ) ) |
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8 | 5 6 7 | sylanbrc | |- ( P e. V -> F : D -1-1-onto-> R ) |