Nuprl Lemma : can-find-first-ext

[T:Type]. ∀L:T List. ∀P:{x:T| (x ∈ L)}  ⟶ 𝔹.  ((∃x:T [first-member(T;x;L;P)]) ∨ (∀x∈L.¬↑(P x)))


Proof




Definitions occuring in Statement :  first-member: first-member(T;x;L;P) l_all: (∀x∈L.P[x]) l_member: (x ∈ l) list: List assert: b bool: 𝔹 uall: [x:A]. B[x] all: x:A. B[x] sq_exists: x:A [B[x]] not: ¬A or: P ∨ Q set: {x:A| B[x]}  apply: a function: x:A ⟶ B[x] universe: Type
Definitions unfolded in proof :  member: t ∈ T ifthenelse: if then else fi  subtract: m can-find-first2 can-find-first1-ext
Lemmas referenced :  can-find-first2 can-find-first1-ext
Rules used in proof :  introduction sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity cut instantiate extract_by_obid hypothesis sqequalRule thin sqequalHypSubstitution equalityTransitivity equalitySymmetry

Latex:
\mforall{}[T:Type].  \mforall{}L:T  List.  \mforall{}P:\{x:T|  (x  \mmember{}  L)\}    {}\mrightarrow{}  \mBbbB{}.    ((\mexists{}x:T  [first-member(T;x;L;P)])  \mvee{}  (\mforall{}x\mmember{}L.\mneg{}\muparrow{}(P  x)))



Date html generated: 2018_05_21-PM-06_34_45
Last ObjectModification: 2018_05_19-PM-04_41_05

Theory : general


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