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Description: Lemma 2 for 1pthd . (Contributed by Alexander van der Vekens, 4-Dec-2017) (Revised by AV, 22-Jan-2021)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | 1wlkd.p | |- P = <" X Y "> |
|
| 1wlkd.f | |- F = <" J "> |
||
| Assertion | 1pthdlem2 | |- ( ( P " { 0 , ( # ` F ) } ) i^i ( P " ( 1 ..^ ( # ` F ) ) ) ) = (/) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | 1wlkd.p | |- P = <" X Y "> |
|
| 2 | 1wlkd.f | |- F = <" J "> |
|
| 3 | 2 | fveq2i | |- ( # ` F ) = ( # ` <" J "> ) |
| 4 | s1len | |- ( # ` <" J "> ) = 1 |
|
| 5 | 3 4 | eqtri | |- ( # ` F ) = 1 |
| 6 | 5 | oveq2i | |- ( 1 ..^ ( # ` F ) ) = ( 1 ..^ 1 ) |
| 7 | fzo0 | |- ( 1 ..^ 1 ) = (/) |
|
| 8 | 6 7 | eqtri | |- ( 1 ..^ ( # ` F ) ) = (/) |
| 9 | 8 | imaeq2i | |- ( P " ( 1 ..^ ( # ` F ) ) ) = ( P " (/) ) |
| 10 | 9 | ineq2i | |- ( ( P " { 0 , ( # ` F ) } ) i^i ( P " ( 1 ..^ ( # ` F ) ) ) ) = ( ( P " { 0 , ( # ` F ) } ) i^i ( P " (/) ) ) |
| 11 | ima0 | |- ( P " (/) ) = (/) |
|
| 12 | 11 | ineq2i | |- ( ( P " { 0 , ( # ` F ) } ) i^i ( P " (/) ) ) = ( ( P " { 0 , ( # ` F ) } ) i^i (/) ) |
| 13 | in0 | |- ( ( P " { 0 , ( # ` F ) } ) i^i (/) ) = (/) |
|
| 14 | 12 13 | eqtri | |- ( ( P " { 0 , ( # ` F ) } ) i^i ( P " (/) ) ) = (/) |
| 15 | 10 14 | eqtri | |- ( ( P " { 0 , ( # ` F ) } ) i^i ( P " ( 1 ..^ ( # ` F ) ) ) ) = (/) |