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Description: Lemma for isthincd2 and thincmo2 . (Contributed by Zhi Wang, 17-Sep-2024)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | isthincd2lem1.1 | |- ( ph -> X e. B ) |
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| isthincd2lem1.2 | |- ( ph -> Y e. B ) |
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| isthincd2lem1.3 | |- ( ph -> F e. ( X H Y ) ) |
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| isthincd2lem1.4 | |- ( ph -> G e. ( X H Y ) ) |
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| isthincd2lem1.5 | |- ( ph -> A. x e. B A. y e. B E* f f e. ( x H y ) ) |
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| Assertion | isthincd2lem1 | |- ( ph -> F = G ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | isthincd2lem1.1 | |- ( ph -> X e. B ) |
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| 2 | isthincd2lem1.2 | |- ( ph -> Y e. B ) |
|
| 3 | isthincd2lem1.3 | |- ( ph -> F e. ( X H Y ) ) |
|
| 4 | isthincd2lem1.4 | |- ( ph -> G e. ( X H Y ) ) |
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| 5 | isthincd2lem1.5 | |- ( ph -> A. x e. B A. y e. B E* f f e. ( x H y ) ) |
|
| 6 | oveq1 | |- ( x = z -> ( x H y ) = ( z H y ) ) |
|
| 7 | 6 | eleq2d | |- ( x = z -> ( f e. ( x H y ) <-> f e. ( z H y ) ) ) |
| 8 | 7 | mobidv | |- ( x = z -> ( E* f f e. ( x H y ) <-> E* f f e. ( z H y ) ) ) |
| 9 | oveq2 | |- ( y = w -> ( z H y ) = ( z H w ) ) |
|
| 10 | 9 | eleq2d | |- ( y = w -> ( f e. ( z H y ) <-> f e. ( z H w ) ) ) |
| 11 | 10 | mobidv | |- ( y = w -> ( E* f f e. ( z H y ) <-> E* f f e. ( z H w ) ) ) |
| 12 | 8 11 | cbvral2vw | |- ( A. x e. B A. y e. B E* f f e. ( x H y ) <-> A. z e. B A. w e. B E* f f e. ( z H w ) ) |
| 13 | 5 12 | sylib | |- ( ph -> A. z e. B A. w e. B E* f f e. ( z H w ) ) |
| 14 | oveq1 | |- ( z = X -> ( z H w ) = ( X H w ) ) |
|
| 15 | 14 | eleq2d | |- ( z = X -> ( f e. ( z H w ) <-> f e. ( X H w ) ) ) |
| 16 | 15 | mobidv | |- ( z = X -> ( E* f f e. ( z H w ) <-> E* f f e. ( X H w ) ) ) |
| 17 | nfv | |- F/ k f e. ( X H w ) |
|
| 18 | nfv | |- F/ f k e. ( X H w ) |
|
| 19 | eleq1w | |- ( f = k -> ( f e. ( X H w ) <-> k e. ( X H w ) ) ) |
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| 20 | 17 18 19 | cbvmow | |- ( E* f f e. ( X H w ) <-> E* k k e. ( X H w ) ) |
| 21 | oveq2 | |- ( w = Y -> ( X H w ) = ( X H Y ) ) |
|
| 22 | 21 | eleq2d | |- ( w = Y -> ( k e. ( X H w ) <-> k e. ( X H Y ) ) ) |
| 23 | 22 | mobidv | |- ( w = Y -> ( E* k k e. ( X H w ) <-> E* k k e. ( X H Y ) ) ) |
| 24 | 20 23 | bitrid | |- ( w = Y -> ( E* f f e. ( X H w ) <-> E* k k e. ( X H Y ) ) ) |
| 25 | eqidd | |- ( ( ph /\ z = X ) -> B = B ) |
|
| 26 | 16 24 1 25 2 | rspc2vd | |- ( ph -> ( A. z e. B A. w e. B E* f f e. ( z H w ) -> E* k k e. ( X H Y ) ) ) |
| 27 | 13 26 | mpd | |- ( ph -> E* k k e. ( X H Y ) ) |
| 28 | moel | |- ( E* k k e. ( X H Y ) <-> A. k e. ( X H Y ) A. l e. ( X H Y ) k = l ) |
|
| 29 | 27 28 | sylib | |- ( ph -> A. k e. ( X H Y ) A. l e. ( X H Y ) k = l ) |
| 30 | eqeq1 | |- ( k = F -> ( k = l <-> F = l ) ) |
|
| 31 | eqeq2 | |- ( l = G -> ( F = l <-> F = G ) ) |
|
| 32 | eqidd | |- ( ( ph /\ k = F ) -> ( X H Y ) = ( X H Y ) ) |
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| 33 | 30 31 3 32 4 | rspc2vd | |- ( ph -> ( A. k e. ( X H Y ) A. l e. ( X H Y ) k = l -> F = G ) ) |
| 34 | 29 33 | mpd | |- ( ph -> F = G ) |